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)
رَأَيْتُ رَسُولَ اللهِ ﷺ أَذَّنَ فِي أُذُنَيِ الْحَسَنِ حِينَ وَلَدَتْهُ فَاطِمَةُ بِالصَّلَاةِ