Bukhari

Hadith Commentary:
(1)
From this hadith, it is understood that a person should choose such words for himself that are not contrary to his honor and dignity; one should avoid such bad words and bad names that are against human respect.
(2)
In the hadith, the use of the word "laqis" is recommended instead of "khabith," even though both have the same meaning, but the word "khabith" and its apparent meaning were against human dignity; therefore, it was advised to refrain from it. The Messenger of Allah (sallallahu alayhi wa sallam) himself would also replace bad names with good ones.
(Fath al-Bari: 10/692)

Hadith Commentary: Benefits and Issues: ➊
This hadith proves that just as sitting on a grave is a cause of its disrespect and is impermissible, in the same way, praying facing towards it is a cause of its veneration, or at the very least, it resembles such veneration.
For this reason, Mulla Ali Qari has written:
If this is truly for the veneration of the grave or the person in the grave, then the one venerating becomes a disbeliever.
(Fath al-Mulhim, vol. 2, p. 507)
➋
When sitting on a grave is not permissible, then how can urinating or defecating on it be permissible, which is an extremely indecent and reprehensible act?
Imam Malik rahimahullah interprets the prohibition of sitting as referring to this (i.e., urinating or defecating on the grave).

Benefits and Issues:
Since the words "khubth" and "khabeeth" are also applied to false beliefs of disbelief (lies) and unlawful actions, therefore, it has been instructed that a Muslim's tongue should remain pure from inappropriate words.