Jami At Tirmidhi
2720
Hasan Sahih+3

Narrated Ibn 'Umar:that a man gave the Salam to the Prophet (ﷺ) while he was urinating, but the Prophet (ﷺ) did not return the Salam to him

Hasan SahihAhmad Muhammad Shakir
Hasan SahihAl-Albani