It is narrated from Sayyidah Aishah (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) would take Sayyiduna al-Hasan (may Allah be pleased with him) and hold him close, and say: "O Allah, this is my son, so love him, and love whoever loves him."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 2572