ENOfficial
Abu Rafi' told th at he saw God's messenger uttering the call to prayer in the ear of al-Hasan b. ‘Ali when Fatima gave birth to him. Tirmidhi and Abu Dawud transmitted it, Tirmidhi saying this is a hasan sahih tradition.
Source: sunnah.com
Other translations
Arabic
وَعَن أبي رافعٍ قَالَ: رَأَيْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أذَّنَ فِي أُذُنِ الحسنِ ابنِ عليٍّ حِينَ وَلَدَتْهُ فَاطِمَةُ بِالصَّلَاةِ. رَوَاهُ التِّرْمِذِيُّ وَأَبُو دَاوُدَ. وَقَالَ التِّرْمِذِيُّ: هَذَا حَيْثُ حسن صَحِيح
sunnah.com