Our Lord, indeed we have heard a caller calling to the faith, [saying], ‘Believe in your Lord,’ so we have believed.

رَّبَّنَا إِنَّنَا سَمِعْنَا مُنَادِيًا يُنَادِي لِلْإِيمَانِ أَنْ آمِنُوا بِرَبِّكُمْ فَآمَنَّا

Rabbanaa innanaa sami’naa munaadiyan yunaadee lil’eemaani an aaminoo birabbikum fa’aamannaa

Surah Al-Imran,verse 193

(“Our Lord! Verily, we have heard the call of one calling to faith,”), a caller who calls to faith, referring to the Messenger of Allah ,

(`Believe in your Lord,’ and we have believed), accepted his call and followed him.