Companions of the Prophet
حَدَّثَنَا حَجَّاجُ بْنُ الْمِنْهَالِ، حَدَّثَنَا شُعْبَةُ، قَالَ أَخْبَرَنِي عَدِيٌّ، قَالَ سَمِعْتُ الْبَرَاءَ ـ رضى الله عنه ـ قَالَ رَأَيْتُ النَّبِيَّ صلى الله عليه وسلم وَالْحَسَنُ عَلَى عَاتِقِهِ يَقُولُ " اللَّهُمَّ إِنِّي أُحِبُّهُ فَأَحِبَّهُ ".Narrated Al-Bara:I saw the Prophet (ﷺ) carrying Al-Hasan on his shoulder an saying, "O Allah! I love him, so please love him
From Sahih al-Bukhari, whose reports the scholars accept as authentic.