Sources of Islam
The Quran is the holy book of Islam. Muslims consider the Quran to be the exact word of God in the Arabic language. Muslims believe that it was transmitted by the Angel Gabriel through the Prophet Muhammad. At the Quran's heart is the teaching of monotheism(the Oneness of God), but it also provides guidance for every part of a believer's life, including aspects that in the West would be considered social, political or legal, and not religious. The Quran is considered by Muslims to complete God's earlier revelations and is meant for all humanity, not for any exclusive groups.
Quran cannot be changed by anyone as God protected it, as it unchanged since it received. A number of followers had carefully memorized each of the revelations of qur'an, word for word. The Quran is considered to be untranslatable because no other language carries the full range of often subtle meaning that the Arabic of the Quran can convey. Muslims regard translations of the Quran in other languages to be interpretations rather than true translations because of the Quran's linguistic beauty, poetical eloquence and clear erudition in the Arabic language.
The Hadith are the reports of the sayings, deeds and approvals of the Prophet Muhammad. The Prophet's sayings and deeds are also called his Sunnah, or example.
Muhammad is the very last Prophet and Messenger of God to mankind. He is considered to be the summation and the culmination of all the prophets and messengers that came before him. Hence, it is the life history of the Prophet Muhammad which provides examples of daily living for the whole mankind. He was entrusted with the power of explaining, interpreting and living the teachings of the Quran.
The sources of legislation in Islam are the Quran and the Hadith.