﴿ حَقِيقٌ عَلَىٰٓ أَن لَّآ أَقُولَ عَلَى ٱللَّهِ إِلَّا ٱلْحَقَّ ۚ قَدْ جِئْتُكُم بِبَيِّنَةٍۢ مِّن رَّبِّكُمْ فَأَرْسِلْ مَعِىَ بَنِىٓ إِسْرَٰٓءِيلَ ﴾

“so constituted that I cannot say anything about God but the truth. I have now come unto you with a clear evidence from your Sustainer: let, then, the children of Israel go with me!"”

Please check ayah 7:106 for complete tafsir.