Musannaf Ibn Abi Shayba 36:455

Waki’ narrated to us, from Malik ibn Mighwal, from Talha ibn Musarrif, who said: The Muslims were defeated on the day of Hunayn, so it was called out to them, "O companions of Surah al-Baqarah!" He said: So they returned, and they had *hunayn*—meaning weeping.