The science of Hadith deals with Prophet Muhammad's life, especially his words and actions, and the actions he approved of in others. In this section, we will restrict ourselves to his own words and actions. These words and their meanings are his alone, for they were not included in the Qur'an, the Recited Revelation and whose meaning and wording belong to God exclusively. His actions include those whose rule and authority we are obliged to follow as laws, and his personal affairs, which are a source of spiritual reward and blessing if followed.
The science of fiqh (Islamic law) does not concern itself with the Prophet's personal affairs. The fuqaha' (jurists) consider that if those affairs touch upon the voluntary and purposed acts, they should be dealt with under the relevant law. However, if they are matters of the Prophet's personal likes and dislikes, which are not a basis for legislation, they are of no concern to the fuqaha'. According to the muhaddithun (scholars of Hadith, or Traditionists), everything related to the Messenger is included in the meaning of Hadith (Tradition) and concerns the Traditionists.
The Sunna is the record of the Messenger's every act, word, and confirmation, as well as the second source of Islamic legislation and life (the Qur'an is the first one). All scholars of religious sciences, and sometimes those of the natural scientists, use it to establish the principles of their disciplines and to solve difficulties. The Qur'an and authentic prophetic Traditions enjoin Muslims to follow the Sunna.
The Qur'an and the Sunna are inseparable. The Sunna clarifies the ambiguities in the Qur'an by expanding upon what is mentioned only briefly in it, specifies what is unconditional, enables generalizations from what is specifically stated, and particularizations from what is generally stated.
For example, how to pray, fast, give alms, and make pilgrimage was established and expounded in the Sunna. So were such principles or legislation that no one can inherit from the Prophet, killers cannot inherit from their victims, the meat of domestic donkeys and wild animals cannot be eaten, and men cannot marry a wife's female cousins if she is still living. Indeed, the Sunna is relevant to all aspects of Islam, and Muslims must design their lives according to it. For this reason, it has been studied and transmitted to each new generation with almost the same care as the Qur'an.
The Messenger ordered his Companions to obey his Sunna absolutely. He spoke distinctly, so they could understand and memorize his words, and encouraged them to convey his every word to future generations. Sometimes he even urged them to write his words down, for: "Whatever I say is true." The Companions were fully attentive to what his words and deeds and showed a great desire to mold their lives to his, even in the smallest details. They regarded his every word and deed as a Divine trust to which they must adhere and follow as closely as possible. Viewing his words as Divine gifts, they internalized and preserved them and transmitted them to future generations.
As truthfulness is the cornerstone of the Islamic character, the Companions did not lie. Just as they did not distort or alter the Qur'an, they did their best to preserve the Traditions and entrust them to future generations by either memorizing them or writing them down. Among the Hadith compilations made during the time of the Companions, three are very famous: Al-Sahifa al-Sadiqa by 'Abd Allah ibn 'Amr ibn al-'As, Al-Sahifa al-Sahiha by Hammam ibn Munabbih, and Al-Majmu' by Zayd ibn 'Ali ibn Husayn.
The Companions were extremely conscientious in relating the Traditions. For example, 'A'isha and 'Abd Allah ibn 'Umar would relate them word for word, not changing even one letter. Ibn Mas'ud and Abu al-Darda' would tremble, as if feverish, when asked to report a Tradition.
Caliph 'Umar ibn 'Abd al-'Aziz (ruled 717-20 ce) ordered that the orally preserved and circulated individual Tradition compilations be written down. Such illustrious figures as Sa'id ibn al-Musayyib, Sha'bi, 'Alqama, Sufyan al-Thawri, and Zuhri pioneered this sacred task. They were followed by the greatest specialists, who were entirely focused on the Traditions' accurate transmittal, as well as studying their meaning and wording and their narrators' careful critiques.
Thanks to these Traditionists, we have the second source of Islam in its original purity. Only through studying the Prophet's life and then conforming our own to it can we gain God's good pleasure and travel the way leading to Paradise. The greatest saints receive their light from this "sun" of guidance, Prophet Muhammad, and send it to those in darkness so that they may find their way.