Shaikh Abul-Muhsin al-‘Abbad hafidhuhallah was asked:
Question: Does the night gown enter into Isbaal because it is not worn with the purpose of adornment nor to pray in?
Answer: “It is not allowed to have Isbaal, whether in the pajamas or other than the pajamas…”
[Sharh Sunan Ibn Majah no. 160]
Shaikh Salih al-Fawzan was asked:
Question: May Allah be good to you, oh possessor of virture. This questioner says: is it allowed for men to have Isbaal in the clothing that is specific for the house or for sleep?
Answer: “Isbaal is not allowed for a man in general, not in the house nor in other than it from the clothing specific for the house. The Messenger (ﷺ) said:
مَا أَسْفَلَ مِنَ الْكَعْبَيْنِ مِنَ الإِزَارِ فَفِي النَّارِ
The part of an Izar which hangs below the ankles is in the Fire.
[Bukhari no. 5787]
He didn’t say except when in the house. So a man avoids Isbaal, whether in the house or outside the house. Yes”
Faisal Ibn Abdul Qaadir Ibn Hassan