It could not be known from any authentic tradition, but a study of its subject matter shows that this Surah also was sent down in the same period in which the Surahs Al-Mumin, As-Sajdah and Ash-Shura, were sent down. It appears that the revelation of this series of the Surahs began when the disbelievers of Makkah were planning to put an end to the Holy Prophet's life. Day and night they were holding consultations in their assemblies as how to eliminate him, and even an attack on his life also had been made as has been clearly referred to in vv. 79-80.