Sunan Ibn Majah 1208
سنن ابن ماجه#1208SahihIt was narrated that Mughirah bin Shu’bah said:“The Messenger of Allah (ﷺ) said: ‘If anyone of you stands after two Rak’ah, if he has not yet stood up fully, let him sit down again, but if he has stood up fully, then let him not sit down, and let him perform two prostrations for forgetfulness (Sahw).’”
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Fouad Abd al-BaqiSahih
Zubair Ali ZaiHasan
In-book reference: 5:406