Narrated 'Ikrimah:"After Salat As-Subh, it was said to Ibn 'Abbas that so-and-so - one of the wives of the Prophet (ﷺ) - has died, so he prostrated. So it was said to him: 'Do you prostrate at this hour?' So he said: 'Has not the Messenger of Allah (ﷺ) [already] said: 'If you see a sign then prostrate?' Then which sign is grater than the passing of (one of) the wives of the Prophet (ﷺ)?

English translation · Jami' at-Tirmidhi