Abu Dawud
The Rites of Hajj
Book Number: 004 / Hadith Number: 1942
Narated By AbuBakrah : The Prophet (pbuh) gave a sermon during his hajj and said: Time has completed a cycle and assumed the form of the day when Allah created the heavens and the earth. The year contains twelve months of which four are sacred, three of them consecutive, viz. Dhul-Qa'dah, Dhul-Hijjah and Muharram and also Rajab of Mudar which comes between Jumadah and Sha'ban.