Tradition 17
Through successive chain of transmitters, Shaikh Sadooq relates from the Holy Prophet Mohammad (s.a.w.s) that he said, that Prophet Moosa bin Imran (a.s) supplicated to Allah and said,
"O my Lord! My brother has died, thus forgive him."
It was revealed to him,
"O Moosa! If you desire, I shall forgive all the people from the beginning until the end, except the murderers of Husain (a.s), for I shall surely take revenge from them."
source : http://www.maaref-foundation.com