Fiqh-us-Sunnah Volume 5, Hajj and ‘Umrah, Fiqh 5.096A.

Section : Taking a Bath.

It is desirable that one should take a bath before encamping in Arafah. Ibn ‘Umar used to take a bath on the eve of the Day of Arafah, as reported by Malik. Similarly ‘Umar (may Allah be pleased with him) used to take a bath in Arafah while he was in the state of ihram.