Ahmad bin Mohammad bin Abdillah bin Ayyash Al-Hafez narrated from the judge, Abdul Baqi bin Fali , from Husain bin Mohammad, from Sulaymaan bin Qarm, from Mohammad bin Shaiba, from Dawud bin Ali , from his father, from his grandfather, Abdullah bin Abbas, who said:
The MESSENGER OF ALLAH (SWT) said to ALI BIN ABI TALEB (ASWS):
O ALI (ASWS) , Jibraeel said something about you that made me extremely happy and pleased me. He (Jibraeel) said: O MOHAMMAD (SAWW)! ALLAH (SWT) told me to convey His Salaam to you and to tell you that ALI (ASWS) is the Imam of Guidance; he is the light in darkness; and he is My decisive proof on the people of the world.
He is the most truthful and the greatest separator of right from wrong. I forbid Myself to allow those who love him, follow him, and follow the Imams after him, to enter Hell. I forbid Myself to allow those who do not accept his Wilayat and do not follow him and the Imams after him to enter Paradise.
I have most certainly committed to fill Hell with his enemies from among the people and the jinn, and to fill Paradise with his Shia and friends from among My creatures.
(Ref: Bihar Volume 37 Page 113 Hadees No.88)