I saw the Messenger of Allah ﷺ uttering the call to prayer (Adhan) in the ear of al-Hasan ibn Ali when Fatimah gave birth to him. (Using translation from Abū Dāʾūd 5105)
رَسُولَ اللهِ ﷺ أَذَّنَ فِي أُذُنِ الْحَسَنِ بْنِ عَلِيٍّ ؓ بِالصَّلَاةِ حِينَ وَلَدَتْهُ فَاطِمَةُ ؓ