הלכה אויף ויקרא 21:11

That a High Priest shall not defile himself with any dead, even if they are relatives, as it is said, “Nor defile himself for his father or mother….” (Lev. 21:11).

That a High Priest shall not go (under the same roof) with a dead body, as it is said, “Neither shall he go in unto any dead body (nor defile himself)” (ibid. 21:11). It has been learnt by tradition that a priest, who does so, violates the prohibition, “Neither shall he go in….”, and also the prohibition, “He shall not defile himself”.

Not to make a bald spot for the dead, as it is said, “Nor make any baldness between your eyes for the dead” (Deut. 14:1).