INTRODUCTION
The First Stage: Foundation or Period of Revelation (The Era of the Prophet Saw 609-632 CE)
This period of the development of Islamic law is consider the most important period as it lays down the foundation for other developments, which happened in the later  stages.  It began with the commencement of the Prophet Hood of Muhammad saw in 609 CE and ended with the demise of the Prophet saw in 632 CE.  In this period, Islamic law went through two phases of development, the first of which was when the Prophet saw was in Mecca and the second was when he was in Medina.

CONTENT
Legal in Mecca
His time of preaching in Mecca lasted for 12 years 5 months and 13 days. The Prophet's revelation when he was in Mecca brought the principle of community formation, a man of dignity who was righteous and maintaining a relationship with God.  For that reason, the Mecca era has not had any amalgamation, such as sale and crime.  It is because of the major focus of the da'wah and the teachings conveyed by him by focusing on forming the true faith and correcting morality.
When you are in Mecca you face opposition from Quraish pagans like torture, threats and economic sanctions.  The pressures faced caused his Companions to migrate for the first time to Ethiopia.  Then he himself went to Ta'if to seek support, but was driven and thrown by stones by the youth there.  The da'wah that he performed while he was in Mecca encompassed two stages, namely: Dawah is difficult: takes about 3 years.  The dakwah center was held at the house of Al-Arqam ibn Abu al-Arqam.  The purpose of da'wah time is only among the nearest relatives.  This is as explained by the word of God which means: And warn your nearest relatives (surah al-syu'ara verse 214) Da'wah is very clear.  That is with the decline of the verse which tells you to call upon all people.  Among the legislative features are also the principles of da'wah that were carried out by His Majesty in Mecca with emphasis on the following:  Cleans the creed and invites them to obey Allah, believing in the day of resurrection, heaven and hell.  They are also directed to look into the occurrence of stars, heavens and earth to take lessons from all these events. Using a gentle-minded approach to da'wah. Summoning to commendable morals and abandoning all customs contrary to Islamic law. Invites to use sensible intellect and abandon taklid, religious and customary ancestry. Less brings a verse related to the legislative form of life and life. Hence, most of the verse descended from Mecca was related to the creed, morality and direction to take lessons from the stories and the history of the past Explain the general principle that manages to care for, mitigates harm and commits virtue. In conclusion, Mecca was the period of decline in the Qur'an for that period of time with the Mecca verses.  The number of Muslims still small and the people who embraced Islam at that time were poor and weak.  Hence, the Muslims are oppressed and have not been known as a strong and feared Muslim.

Legal in Medina
The Medina era is the second stage which begins in the year of Hijrah and ends after his death in 10 AH and takes the precise time of 9 years 9 months 9 days.  Therefore, with His death the revelation ended and the religion of Islam was complete.  That condition as explained by the word of God which means: Today I have perfected for you your religion, and I have satisfied My favor to you, and I have been converted to Islam as a religion for you.
While in the Medina he had to face various categories of societies of various tribes, folk and religious followers, such as Jews, Christians and the hypocrites. Therefore, his action was to compete between the Muhajirin and the Ansar.  He also acted in the form of the Islamic state of Medina as well as calling upon the teachings of Islam in full accord with the word of Allah which means "to come to the path of your Lord (O Muhammad SAW) with the wisdom of wisdom and advice of good teaching and debate with them (which you summon it) in a better way "surah A-Nahl verse 125
The current legislation focuses on the scope of the particular scope of which: the establishment of laws relating to worship, such as fasting and zakat obligations. The law that deals with the laws of the Qur'an and is obliged to fight against the infidels. The laws relating to Hu dud and criminal law dealing with the will and inheritance of the family law as well as marriage and divorce the oath and the vow of judiciary and statehood.

The Principles of Basic Legislation

The main reason for the decline of the Quran is to establish and settle the position of mankind. For that the establishment of Islamic law as in the Quran and Hadith by focusing on the five main principles, namely: The law gradually: the Qur'an is not revealed at the same time as well as the wisdom of reducing the law this way is to ease the acceptance of the people, to encourage them to practice it and to facilitate them to memorize the law and to understand the reasons and background of the law is revealed. For example, the prescribed law relates to drinking alcohol that was revealed in four stages or contained in four separate sentences.  The gradual concept in the legislation can be divided into two forms:
Gradually the number of angles: It means Islamic legislation is not lowered at one time and not at once.  Gradually the number of laws and legal times can be clearly illustrated by the corners of the verse revealed in Mecca and Medina.  The example of the gradual angle of time and the number of laws is:
The law of Mecca is more mujmal or general.
On the night of Isra 'Mikraj a year before the Hijrah was prayed five times.
In the first year of hijrah, the obligations of war or jihad against the infidels.  In the same year, it was also legalized that marriage and marriage were legalized.
In the second year of hijrah, it is permissible to fast in the month of Ramadan, zakat, two-day prayers, the sacrifice, the direction of the Qiblah during the prayer from Baitul Maqdis to the Ka'bah and to pass the war booty.
In the third year of hijrah the establishment of legislation on inheritance or inheritance and dissolution.
In the fourth year of the migration the qasar prayers were observed when the traveler, in fear or war, the punishment of adultery, tayammum and qazaf.
In the sixth year of God describes the law of peace reconciliation.  In that year God also banned wine, gambling and magic fate.
In the seventh year it was forbidden to eat meat of donkeys and legal rules on agriculture and irrigation.
In the eighth year, the law on theft was imposed.
In the ninth year of Hijrah the law was conveyed to Lian and prevent the infidels from entering Mecca.
In the tenth year it is forbidden to usury. It is obligatory for a law for example: obligations of prayer, fasting obligations, and obligations of zakat, ban of liquor, war and jihad.
The Law Reduces the Taklif
Sharia and legal in Islam are more convenient than in previous legislation.  How to cleanse the stool in the previous shari'a by removing unclean parts, while in Islamic law, the division is purified.
At the time of the Prophet there was no law on things that had never been legalized.  For example, the Prophet did not establish the prayers of circumcision in congregations because of fear that he would be misled.
Prayer required for Muslims is only five times a day.
Zakat of property to every individual, even those who are capable of and a small part of the property.
The things that are prohibited by syarak are fewer than those passed.  Among the illicit things is that which brings harm and is specifically stated.
Fasting is deferred per month within a year.
Legislation in line with human benefit there are some shari'a set by Allah and then canceled. For example:
At the beginning of the prayer to the Qiblah towards Baitul Maqdis, then abolished and converted to the Ka'bah in Mecca.
Iddah for the wife of the deceased husband was originally a year later abolished and replaced with the termination of 4 months 10 days.
The Prophet had previously kept the deed of sacrifice.  Subsequently repealed and replaced with the law shall save a third of it.
Legal Features of the Prophet's Times
The law and the development of the Fiqh which lasted throughout the life of Rasulullah s.a.w have formed a special privilege.  In those days was the time of legal formation.  Among the legal privileges of the Prophet's time are:  All the laws formed at that time are only guided and based on only one source, namely Divine revelation.  The revelation is either in the form of Revelation Matlu ie the Quran and the Non-Matheus Revelation ie all the Prophets of Rasulullah s.a.w.
The power of the law and the interpretation of all the writings lies in him alone.  Context in the issue of revelation is not revealed to clarify the law, He will adjudge.  Sometimes the ijtihad is supported by revelation, sometimes it is corrected by the revelation that is inaccurate and the revelation of the revelation is considered as a shari'a.  In those days there were some friends who were authorized and empowered by him to admit the problems that arise.  However, the ijtihad of the companions ceased to acknowledge him, whether it is legal or otherwise.
There is no form of dispute or contradiction in the same problem.  That is because he still existed and became a place of direct contact as well as acting as a legislator. The perfection of Islamic legislation was formed as soon as the end of the age.  For this reason, the decline of revelation is also the hadith of s.a.w who acts as the interpreter to the Qur'an when he died.
The Prophet s.a.w opened the room for the best friends and mujtahid especially to perform the ijikihad.  This is because the Quranic text and his hadiths sometimes do not explain all the laws of juz'i.  For that, in the no problem with it, the companions are justified and appearing for the purpose of ijtihad. At that time there is still no form of Fiqh or its knowledge in terms of the term.  That is because the majority of the laws required by the Muslims are obtained through his s.a.w.  Revelation is still being revealed and is not necessary to any legal person.
There is a concept of cancellation and replacement of some laws.  Examples are: wills.  Islam is obligated to be lawful.  Then the law was canceled with the fall of the verse and the law of the heritage. The legislation that was formed and set in the days of the Prophet s.a.w was more practical and the thing that actually happened at that time.  That's why there is no law based on the assumptions that will come.

CONCLUSION
As a conclusion, the foundation period marked the beginning of the evolution of fiqh as the science of deducing laws from Quran and Sunnah were laid by Prophet. The foundation of mazhab took shape as the Prophet guided and trained the companions in ijtihad.