WIth regards to the student of knowledge staying away from gatherings of laghw, Shaykh al ‘Uthaymeen rahimahullaah commented:
As for his (the author’s) statement: turning away from gatherings of futile speech…
Then laghw (futile speech) is of two types:
i) laghw which contains no benefit and no harm
And ii) laghw which contains harm
As for the first type – then it is not befitting for a person who has intellect to allow his time to disappear in this because it is (nothing but) loss.
As for the second type – this is something evil; it is forbidden for him to spend his time in this because it is evil and forbidden.
And it is as if the author was taking the interpretation (of this word) upon the second meaning – which is the forbidden laghw. And without doubt, the person is not allowed to sit at gatherings which contain that which is forbidden because Allaah, the Most High, says:
And it has been revealed to you in the Book that if you when you hear the aayaat of Allaah being denied and mocked, then do not sit with them (those people) until engage in speech other than that.
(If you were to stay with them) then you would be just like them.
Soorah an Nisaa (4) aayah 140
So it is obligatory upon whoever sits in a gathering of munkar (evil) to forbid that evil. Then if the situation is rectified, that is what is desired. And if it is not rectified and they (the people) continue upon their evil, then it is obligatory upon him to leave (them).
This is in contrast to what some of the common people falsely believe, saying:
“Indeed Allaah’s Messenger sall Allaahu ‘alaihi wa sallam said: Then if he is not able (to change the evil with his tongue or hand) then let him (hate it) with his heart.” And I hate this evil in my heart.”
And (yet) he is sitting with its people.
So it is said to him:
If you truly were someone who hated it, you would not sit with them – because it is not possible that a person sits in a gathering whilst hating those people in it.
As for something which you hate and (yet) you sit (there) through your own choice, then your claim of hating it is not correct and true.
(Sharh hilyah taalib il ‘ilm p47- 48 of Shaykh Muhammad ibn Saalih al ‘Uthaymeen rahimahullaah, translated by Nasser ibn Najam