How is this hadeeth classified through the Fuqahaa:
4 Rakaats Before Salaat al-Isha. Hazrat Sa’eed Ibn Jubair (radhiallahu anhu) narrates that the Sahaabah (radhiallahu anhum) used to regard the performing of four rakaats before the fardh of isha as mustahab.[Qiyaamul-Layl of Marwazi pg.58]
And where can we find this hadeeth.
Allamah Marwazi [ra] was a Muhaddith in his own right who would narrate Ahaadith with his own chain of narrators. He has narrated this Hadith with his chain of narrators in his Qiyaamul-layl. However, this book can only be found in manuscript form which we are not in possession of. The published version of his book is the abridged version without the chain of narrators. Therefore, we cannot comment on its authenticity.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai