I saw Hasan b. 'Ali upon the shoulders of Allah's Apostle (ﷺ) and he was saying: O Allah, I love him, and love him Thou.
Sahih Muslim Book 44, Hadith 88
← Previous Hadith I went along with Allah's Messenger (ﷺ) at a time during the day but he did not talk to me and I did not talk to him until he reached the market of Bani Qainuqa`. He came back to the tent of Fatima and said: Is the little chap (meaning Hasan) there? We were under the impression that his mother had detained him in order to bathe him and dress him and garland him with a sweet garland. Not much time had passed that he (Hasan) came running until both of them embraced each other, thereupon Allah's Messenger (ﷺ) said: O Allah, I love him; love him Thou and love one who loves him (Hasan).

Sahih Muslim Book 44, Hadith 87 Next Hadith → I saw the Messenger of Allah (ﷺ) with Al-Hasan b. 'Ali placed upon his shoulders and he was saying: O Allah, I love him, and love him Thou.

Sahih Muslim Book 44, Hadith 89