Is it permissible to delay the rawatib of 'Isha' until before sleeping?

Question:
May Allah reward you, Honorable Shaykh. This questioner says: A man prays the rawatib of 'Isha' before sleeping, around ten-thirty at night. A man prays the rawatib of 'Isha' before sleeping, around ten-thirty at night, and a man rebuked him, saying it must be after that, meaning when you go to the house and you are praying it, meaning from the time you go to the house you pray it. What is the correctness of his statement?

Answer:
That is, hastening is a good initiative. As for it not being valid or permissible, it is not valid but it is permissible. As long as the time remains, as long as the time for the obligatory prayer remains, the rawatib after the prayer is valid within the time. However, the better course is to hasten with it so that one does not forget it or become occupied and neglect it. The better course is to hasten and for it to be immediately after the obligatory prayer. This involves hastening to obedience, and it also involves, yes, fear of forgetting it or fear of becoming occupied and neglecting it. There is no doubt that hastening with it is better. As for it being said that it is not valid if delayed, no, as long as it is within the time, it is valid. Yes.