The Prophet ﷺ said about Hasan, "O Allah, I love him, so love him and love whoever loves him."
حدثنا سفيان حدثني عبيد الله بن أبي يزيد عن نافع بن جبير
عن النبي ﷺ قال لحسن اللهم إني أحبه فأحبه وأحب من يحبه
Its isnad is sahih. Ubaydullah bin Abu Yazid Makki, the freedman of the family of Qariz bin Shayba, is a trustworthy successor (tabii), whose reliability was already established at 604 and 1938, and we add here that Ibn Saad gave his biography in Tabaqat 5:354–355, saying, "He was trustworthy and transmitted many hadiths," and Ibn Abu Hatim gave his biography in Jarh wat-Tadil 2/2:337–338.Nafi bin Jubayr bin Mutim, his reliability was already established at 744, and we add here that Ibn Saad gave his biography at 5:152–153, as did Bukhari in Kabir 4/2:82–83, and Ibn Abu Hatim at 4/1:451.This hadith was narrated by Muslim, 2:241, from Ahmad bin Hanbal, with this isnad. It was narrated by Ibn Majah, 142, from Ahmad bin Abdah, from Sufyan bin Uyayna, through him. It was narrated by Bukhari, 4:286–287, at length as part of a longer account, from Ibn Madini, from Sufyan, and it will come again at length also at 8362, through the route of Warqa from Ubaydullah. Through that same route, Bukhari also narrated it at 10:279. It will also come again at length at 10904, through another route from Abu Hurairah.