Reference: Daleel al-Akhtaa.a yaqa’a feehaa al-Haaj wal-Mu’tamir wat-tahdtheer minhaa – Page 69
Question: Some pilgrims visit Jabal ‘Arafah before performing the Hajj or afterwards and pray upon it (at the peak). What is the ruling regarding visiting Jabal ‘Arafah and what is the ruling regarding praying upon it?
Response: Its ruling is as is known from the Sharee’ah ruling and that is that anyone who worships Allaah in a manner that has not been legislated, then he is an innovator. So it is known from this that he who has intended to pray on Jabal ‘Arafah or at the bottom or just touch it or similar to this, which some people do, is an innovation which is disliked and frowned upon. It is said to him: There is nothing special about this mount except that it is a Sunnah for a person to stand at the rocks on the Day of ‘Arafah (9th of Dhul-Hijjah), just as the Prophet (sal-Allaahu ‘alayhi wa sallam) stood at it. The Prophet (sal-Allaahu ‘alayhi wa sallam) stood near the rocks and said:
«I have stood here, however, all of ‘Arafah is a standing place», [Saheeh Muslim].
So based upon this, it is also not befitting for a person to cause difficulty for himself on the Day of ‘Arafah by going to the mount and possibly causing difficulty for his people. Thus, getting tired from the heat and thirst, by doing so, is sinning because he has caused difficulty in a matter which Allaah has not made obligatory for him.