Wathilah bin Al-Asqa' narrated that the Messenger of Allah (s.a.w) said:
"Do not rejoice over the mishaps of your brother so that Allah has mercy on him and subjects you to trials." (AR)
English reference (AR): Vol. 4, Book 11, Hadith 2506 (AR)
Arabic reference (AR): Book 37, Hadith 2694 (AR)