(25) باب التَّحَرِّي
It was narrated that Ibrahim said:
"They used to say: 'If one is not sure of what he estimates is correct, then prostrate twice.'" (AR)
Reference (AR): Sunan an-Nasa'i 1247 (AR)
In-book reference (AR): Book 13, Hadith 69 (AR)
English translation (AR): Vol. 2, Book 13, Hadith 1248 (AR)