Assalaamu alaykum. I would like to know the authenticity of those narrations that mention that the virtue of praying four rak'ahs (units of prayer) after the ʻIshaa' is equal to Laylat Al-Qadr. May Allaah reward you.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.

Some ahaadeeth that are directly attributed to the Prophet have been reported in this regard; however, their chains of narration include weak parts. For instance, Ibn ʻUmar narrated that the Prophet said, "Whoever prays ʻIshaa' in congregation and prays four rakʻahs before he leaves the mosque, it will be equivalent to (the rewards of) Laylat Al-Qadr." [At-Tabaraani in Al-Muʻjam Al-Kabeer and Al-Muʻjam Al-Awsat]

Also, Ibn ʻAbbaas reported that the Prophet said, "Whoever prays four rakʻahs after ʻIshaa', reciting in the first two rakʻahs 'Qul yaa ayyuha Al-Kaafiroon’ (Al-Kaafiroon chapter no. 109) and 'Qul Huwa Allaahu Ahad' (Al-Ikhlaas chapter no. 112), and reciting in the last two rakʻahs 'Alif Laam Meem Tanzeel' (As-Sajdah chapter no. 32) and 'Tabaarak Allathi biyadihi Al-Mulk' (Al-Mulk chapter no. 67), they will be recorded for him like four rakʻahs performed during Laylat Al-Qadr."

Both ahaadeeth were classified as weak by Al-Albaani in his book Silsilat Al-Ahaadeeth Adh-Dhaʻeefah, no. 5060. He then commented:

"However, the hadeeth narrated on the authority of Ibn ʻUmar was authentically reported as a mawqoof hadeeth (i.e. stopped at the level of a Companion) on the authority of a number of Companions without the phrase 'before he leaves the mosque.' It was mentioned in a version cited by Ibn Abi Shaybah in Al-Musannaf (2/72/1) and by Ibn Nasr as well on the authority of Ibn ʻAmr reading, 'Whoever prays four rakʻahs after ʻIshaa', they will be equivalent (in reward) to four like them on Laylat Al-Qadr.' I say: Its chain of narration is saheeh (sound). Ibn Abi Shaybah narrated similar reports on the authority of ʻAa'ishah, Ibn Masʻood, Kaʻb ibn Maatiʻ, Mujaahid, and ʻAbd Ar-Rahmaan ibn Al-Aswad in mawqoof reports (stopped at the level of the Companion), and the chains of narration leading back to them are all authentic, with the exception of Kaʻb's. Although they are mawqoof reports, they come under the ruling on marfooʻ (attributed to the Prophet ) reports, because the contents of the ahaadeeth could not have been based on personal opinion, as is quite clear."

Allaah knows best.