Book of interpretation of the Holy Qur'an.
Surah Muddathir was the first chapter revealed by Jibra-eel (A.S) in his real form. The Prophet (S.A.W) saw him and fell unconscious. The first verses revealed were from Alaq (the Clot)
This book mentions the superiority of surah Ikhlas, Fatiha and of surah Kahf, Yasin and the last two verses of surah Baqarah (the Cow)
Details the verses of fasting, sexual relations with wives, spending in the cause of Allah, divorce, the obligatory prayers, the laws of inheritance, the glimpses of the hereafter, punishment for killing believers intentionally, the veiling of women and guarding of chastity. Punishment for those spreading slander and the accusations of adultery on wives and their refuting it.
The creation of the heavens and earth. Time and significance. Brief history of all the prophets. The oneness and absolute authority of Allah, the creation of man.
Also mentions how divine inspiration was revealed - in the language of the Quraish. The collection and scribe of the prophet, (all Ansari), the Qur'an is the inheritance of the prophet. It is to be recited in a pleasant tone and revised as not to be forgotten, the Qur'an should not be completely recited in a period less than seven days and never for showing off purposes.