Bukhari

Hadith Commentary:
By "hamw" are meant those relatives of the husband with whom marriage to this woman is permissible, such as the husband's brother, nephew (brother's son), nephew (sister's son), paternal uncle, paternal cousin, maternal cousin, etc.—those with whom, in some lawful circumstance, this woman could marry. However, those relatives who are mahram (permanently unmarriageable kin), such as the husband's father, son, etc., are not meant here; it is permissible for them to be alone with her.

Hadith Commentary:
(1)
By "hamw" are meant those relatives who are other than the father and sons, i.e., the husband's brothers, nephews (brother's sons), sister's sons, paternal uncles, maternal uncles, etc., because these relatives are not mahram (permanently unmarriageable kin) to the woman. If the husband passes away or the wife is divorced, marriage with them is permissible.

(2)
The Messenger of Allah (sallallahu alayhi wa sallam) has described these relatives as "death" because generally there is negligence and laxity regarding them, and as a result, dangerous consequences arise. If these individuals are alone with the wife in the absence of the husband, then if the matter is limited to kissing and embracing, it is the destruction of religion, and if it reaches the point of adultery, it is the destruction of life. In this, there is also destruction for the woman, for if the husband finds out, he may divorce her or, out of jealousy, kill her.

(3)
Upon reflection, this hadith can serve as evidence for both of the aforementioned issues.
Wallahu al-musta‘an (And Allah is the One whose help is sought).

Hadith Commentary: Benefits and Issues: It is established from this hadith that performing the ritual bath (ghusl) an odd number of times is preferable. Even if, according to necessity, it exceeds three or five times.