My father quoted from Abdollah bin Jafar Homayri, ‘A man I do not remember his name and was one of our accompanies quoted from Obeid-allah bin Musa, and he from Mohalhil Abdi, and he from Abi Haroun Abdi, and he from Rabiat al-Sadi, and he from Abizar Ghaffari,
“Prophet Muhammad kissed Imam Hassan and Imam Hussein and said, ‘He will not be burned in Hell, the one who likes Hassan and Hussein from the bottom of his heart, even if he has committed as many sins as equal to the number of the sands in the desert. The only exception is for the one who has turned his backs to religion because of his sins.’”
Source: Kamil-Al-Ziarat, Written by Jafar bin Muhammad bin Quluyah, Tehran, Payam-e-Haq Publication, 1381, Page 150, the forth Hadith.
My father quoted from Sad bin Abdollah, and he from his father; and also Abdolrahman bin Abi-Najtan from someone, and he from Abbas bin Valid, and he from his father, and he from Hazrat Abi Abdollah that Prophet Muhammad said, “The one who dislikes Imam Hassan and Imam Hussein will be summoned on the Doomsday with no flesh on his face and I cannot intercede in his behalf either.”
source : tebyan