Those who use FOUL LANGUAGE are of the People of Hell

The Prophet said,

'The people of Hell are five:

1) the weak who lack power (to avoid evil), who follow blindly and do not care for family or property (i.e. they care neither for the benefits of the Hereafter nor of this world);

2) the dishonest who whose greed cannot be concealed even in the case of minor things;

3) a person who would betray you morning and evening regarding your family and your property.'

He also made mention of
4) the miser and the liar

5) and one who is in the habit of abusing people and using obscene and foul language.

[Muslim]