[وأسألُك كلمةَ الحقِّ في الرِّضَا والغضب – I ask You (O Allaah) to make me true in speech in times of pleasure and anger] [Ref 1]

The one who does not utter except the truth during anger and pleasure, then this is a proof of his strong Eemaan and that indeed he is in control of his Nafs. [Ref 2]

[Ref 1: Part of a supplication narrated by Ammaar Bin Yaasir (radiyallaahu-anhu) from the Messenger (sallal-laahu-alayhi-wasallam). Reported by An-Nasaa’ee Number 1305 & found in Saheeh Al-Jaami Number 1301]

[Ref 2: Fiqhul Ad’iyah Wal-Adkaar’ parts 3 & 4’ page 167]