(Tell My bondmen to speak that which is kindlier…)[17:53].
This was revealed about ‘Umar ibn al-Khattab, may Allah be well pleased with him. An Arab man insulted him, and so Allah, exalted is He, commanded him to pardon him.
Said al-Kalbi: “The idolaters were in the habit of harming, verbally and physically, the Companions of the Messenger of Allah, Allah bless him and give him peace. When the latter complained to the Messenger of Allah, Allah bless him and give him peace, Allah, exalted is He, revealed this verse”.
Asbab Al-Nuzul by Al-Wahidi , trans. Mokrane Guezzou