Mowfaq Bin Ahmad in the book Al Manaqib...

Mowfaq Bin Ahmad in the book Al Manaqib, by his chain, from Abu Barzat, said, ‘Rasool-Allah -saww said: The feet of a servant would not move on the Day of Judgment until Allah -azwj Blessed and Exalted Questions him about four (matters) – About his life-time, in what he spent it, and about his body, in what did he indulge it in, and about his wealth, from what did he earn it, and in what did he spend it, and about our -asws love of the People -asws of the Household’.

فقال عمر بن الخطاب: فما آية حبكم من بعدك؟ Umar Bin Khattab said, ‘So what is the sign of (having) your -asws love from after you -saww ? فوضع يده على رأس علي (عليه السلام)- و هو إلى جانبه-، فقال: «إن آية حبي من بعدي: حب هذا، و طاعته طاعتي، و مخالفته مخالفتي».

He -saww placed his -saww hand upon the head of Ali -asws – and he -asws was by his -saww side – and he -saww said: ‘The sign of (having) my -saww loved from after me -saww is (having) the love of this one -asws , and obeying him -asws is obeying me -saww , and opposing him -asws is opposing me -saww ’’.

(Imam Hassan Al-Askari -asws said): ‘Rasool-Allah -saww said: ‘Allah -azwj the Exalted Informed that the one who does not believe in the Quran, so he did not believe in the Torah, because Allah -azwj the Exalted Took upon them (an oath) of the Eman in both these. The Eman is not Accepted in one of the two except with the Eman in the other.

So the one who said, ‘I believe in the Prophet-hood and disbelieves in the Wilayah of Ali -asws , so he did not believe in the Prophet-hood of Muhammad -saww ’’.