Anas b. Malik reported that Allah's Messenger (ﷺ) said to Ubayy b. Ka'b
I have been commanded to recite to you the Sura (al- Bayyinah) which opens with these words (Lam Yakunil-ladhiyna Kafaruu) He said: Has he mentioned to you my name? He said: Yes; thereupon he shed tears of joy.