(The forbidden month for the forbidden month…) [2:194].
Said Qatadah: “The Prophet of Allah, Allah bless him and give him peace, proceeded along with his Companions in the month of Dhu’l-Qa‘dah [intending to perform the pilgrimage] when they were stopped by the idolaters at Hudaybiyyah. The following year, they entered Mecca in the month of Dhu’l-Qa‘dah, performed the lesser pilgrimage (‘umrah) and remained there for three nights. The idolaters were proud that they turned them back on the day of Hudaybiyyah, and so Allah avenged them. He revealed (The forbidden month for the forbidden month…)”.
Asbab Al-Nuzul by Al-Wahidi , trans. Mokrane Guezzou