Is there any authentic Hadith regarding the permissibility of performing the two rak’ah sunnah/nafl after witr, while sitting as many ‘Ulama in my area do?
In principle, one is allowed to offer any Nafl/Sunnah salah while seated, however the reward for that salah will be halved.
Rasulullah (sallallahu ‘alayhi wasallam) is reported to have said:
‘The salah of one who is seated yields half the reward of one who is standing.’
(Sahih Bukhari, Hadith: 1115 and Sahih Muslim, Hadith: 1712)
Similarly, Rasulullah (sallallahu ‘alayhi wasallam) is himself also reported to have offered the two rak’ahs after witr specifically, while seated.
(Sahih Muslim, Hadith: 1721)
However, for Nabi (sallallahu ‘alayhi wasallam), the reward is not halved. He is rewarded in full, even when praying salah while seated.
(Sahih Muslim, Hadith: 1712)
And Allah Ta’ala Knows best,
Answered by: Moulana Muhammad Abasoomar
Checked by: Moulana Haroon Abasoomar