Prophet Muhammad (saww) Says in the sermon of Ghadeer:

معاشر الناس إن فضائل علي بن أبي طالب عليه السلام عند الله عز وجل، وقد أنزلها في القرآن أكثر من أن أحصيها في مقام واحد، فمن أنبأكم بها وعرفها فصدقوه

"O' People! Indeed, the merits of Ali Ibn Abi Talib (as) near Allah, the mighty and the majestic, which are indeed revealed in the Quran, are more numerous than I could recount in one speech. Thus, whenever someone relates them to you and acquaints (you) with them, then believe him."

[Source: Al-Ehtejaaj, Vol. 1, Pg. 83]