What to say upon hearing the Athan (call to prayer) — Du'a 3

يُصَلِّي عَلَى النَّبِيِّ صلى الله عليه وسلم بَعدَ فَرَاغِهِ مِن إِجَابَةِ المُؤَذِّنِ

English meaning

‘One should then send prayers on the Prophet (sal-Allaahu 'alayhe wa sallam) after answering the call of the mu.adhdhin’.