Does one attain unto the reward of night vigil worship (tahajjud) if one sleeps before Isha tim

In the Name of Allah, Most Merciful and Compassionate

May His blessings and peace be on His Beloved Prophet, the best of creation, and his family, companions, and followers

Yes, the reward of night vigil worship (tahajjud) is attained if one sleeps before Isha prayer, or even before Isha time (such as sleeping after praying Maghrib) and then gets up at night to worship. This was stated explicitly by Allama Bajuri, and entailed by the words of Shaykh Ibn Hajar in his Sharh al-Irshad, as mentioned by Shabramullasi in Hashiyat al-Nihaya.

[However, performing Isha in congregation is greater in reward, and should not be left for this.]

And Allah alone gives success.

- Amjad Rasheed.

(Translated by Faraz Rabbani)

السؤال: هل يحصل ثوابُ التهجد لمن نام قبل وقت العشاء واستيقظ في منتصف الليل وصلى العشاء وبعض الركعات ؟ 

الجواب : نعم يحصل ثوابُ التهجد لمن نام قبل فعل صلاة العشاء ولو قبل وقت العشاء أيضاً بأن نام بعد المغرب كما صرح به العلامةُ الباجوري وهو اقتضاه كلام الشيخ ابن حجر في "شرح الإرشاد" كما قال الشبراملسي في "حاشية النهاية" .