´It was narrated that 'Aishah said:` "Whoever tells you that the Messenger of Allah (ﷺ) urinated standing up, do not believe him, for he would not urinate except while squatting."
Explanation & Benefits
Hafiz Muhammad Ameen
29. Commentary:
Aisha radi Allahu anha has described the general practice of the Prophet sallallahu alayhi wa sallam. The mention in previous narrations of urinating while standing refers to occasions outside the home. Obviously, Aisha radi Allahu anha was not aware of this, therefore, this does not negate the authenticity of the sahih hadith. Both are correct in their respective contexts. Most likely, Imam al-Nasa'i rahimahullah, by adding «فی البیت» in the chapter, has indicated towards this very point. And Allah knows best.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 29