Ramban on Leviticus 21:10/רמב"ן על ויקרא כ״א:י׳

1HE SHALL NOT LET THE HAIR OF HIS HEAD GO LOOSE etc. 11. NEITHER SHALL HE GO IN TO ANY DEAD BODY. The phrase [dealing with his hair, in Verse 10], is connected with any dead body in the following verse, thus stating that the High Priest is not to let his hair go loose nor rend his garments for any dead body, neither is he to enter a tent where there is a corpse.