What is the evidence for the invalidity of the Hajj of one who did not spend the night at Muzdalifah?

The questioner : What is the evidence that the Hajj of one who did not spend the night at Muzdalifah is not valid? This question has just come up, and we need to detail the issue of performing Hajj on behalf of another.

The Shaykh : It is his saying (peace and blessings be upon him), which is authentic and explicit, when a man came to him—I think he was from Tayy—and said: "I have not left a mountain without climbing it, nor a valley without descending into it, until I came to the Prophet (peace and blessings be upon him) while he was at Muzdalifah, asking about his Hajj with this great effort: is it valid or not?" So he (peace and blessings be upon him) answered him by saying: First, the Messenger (peace and blessings be upon him) combined the prayer at Muzdalifah with standing at 'Arafah for an hour of night or day; he combined them first with each other. Second, he linked them together such that whoever did that has completed his tasks and his Hajj is complete. The meaning of that is that whoever neglected one of the two combined things, one with the other, has not completed his tasks and has not completed his Hajj. That is, if one stood at 'Arafah for an hour of night or day but went quickly to Mina and did not pray Fajr at Muzdalifah, he has neglected this condition completely, just as if he prayed at Muzdalifah but did not stand at 'Arafah, he has neglected the condition. This is the first point. Therefore, his Hajj is not complete. Yes.