The MESSENGER OF ALLAH (SAWW) said,
“ALLAH (SWT) will register the reward of fasting sixty months for those who fast on the eighteenth day of Dhul Hajja.”
Abi Huraira continued, “That is the day of Ghadeer, the day on which the MESSENGER OF ALLAH (SAWW) held the hand of ALI BIN ABI TALEB (ASWS) and said, ‘Of whomsoever I am his master, this ALI (ASWS) is his master’ Then omar bin khattab (LA) told ALI (ASWS) , ‘Well done, O ALI (ASWS)! You have become my master and the master of every believer.’
(Ref :Bihar Al-Anwar 98:31. Amaali of Sadouq 12. T’araef 147- Manaqeb ibn AI-Moghwell 19)