Verse 30

ذَٰلِكَ بِأَنَّ ٱللَّهَ هُوَ ٱلْحَقُّ وَأَنَّ مَا يَدْعُونَ مِن دُونِهِ ٱلْبَـٰطِلُ وَأَنَّ ٱللَّهَ هُوَ ٱلْعَلِىُّ ٱلْكَبِيرُ

This is because indeed God is the truth and certainly those whom they call upon besides Him are falsehood and that God is The Exalted, The All Magnificent.