Hadith #1034 (Sahih Muslim)
Book: The Book of Prayers
Narrator(s): Busr bin Sa'id
Grade: Sahih

If anyone who passes in front of a man who is praying knew the responsibility he incurs, he would stand still forty (years) rather than to pass in front of him Abu Nadr said: I do not know whether he said forty days or months or years.

Source: https://parallelquran.com/hadith/sahih-muslim-1034/