Usama b. Zaid told that the Prophet used to take al-Hasan and him and say, "0 God, I beseech Thee to love them, for I love them." In a version he told that God's messenger used to take him and put him on his knee, then put al-Hasan on the other knee, and after embracing them say, "0 God, I beseech Thee to have compassion on them, for I have compassion on them."
Bukhari transmitted it.