﴿ إِذْ أَرْسَلْنَآ إِلَيْهِمُ ٱثْنَيْنِ فَكَذَّبُوهُمَا فَعَزَّزْنَا بِثَالِثٍۢ فَقَالُوٓا۟ إِنَّآ إِلَيْكُم مُّرْسَلُونَ ﴾

“Lo! We sent unto them two [apostles], and. they gave the lie to both; and so We strengthened [the two] with a third; and thereupon they said: “Behold, we have been sent unto you [by God]!””

Please check ayah 36:17 for complete tafsir.