1- It is important to choose, for the purpose of bathing the deceased, someone that is trusted, just and knowledgeable about the rulings of the funeral bath.
2- Priority is given to the person appointed or entrusted by the deceased (before his death), then the relatives according to their closeness, on the condition that such a person knows the rulings of the bath; otherwise a more knowledgeable person is chosen for the task.
3- A man bathes men and a woman bathes women, and any of a married couple can bathe the other. This is due to the Prophet's ﷺ statement to A'ishah (may Allah be pleased with her): "You would not be harmed if you were to die before me, as I would wash you, shroud you, pray over you and thereafter bury you." [ Source: Ibn Majah.]
A man or woman can bathe children below the age of seven; but it is forbidden for any Muslim - male or female - to bathe an unbeliever, carry his remains to the funeral, shroud or offer funeral prayer over him, even if this unbeliever is a close relative, such as his father.
4- A martyr who died during a battle is not to be bathed, shrouded or prayed on, but he should be buried in the clothes in which he died.
5- When an aborted fetus - a child that is born of its mother before complete formation, male or female- reaches four months, it is to be bathed, shrouded, prayed over and buried, because after four months it has become a human being.
6- The water used to wash the deceased's body must be pure and legitimate, and the deceased must be bathed in a covered place, just as the presence of anybody not having any business with the bathing process is to be prevented.