Surah Luqman Tafseer

ذَلِكَ بِأَنَّ اللَّهَ هُوَ الْحَقُّ وَأَنَّ مَا يَدْعُونَ مِن دُونِهِ الْبَاطِلُ

That is because Allah, He is the Truth, and that which they invoke besides Him is falsehood;

means, He shows you His Signs so that you may know from them that He is the Truth, i.e., He truly exists and is truly divine, and that all else besides Him is falsehood. He has no need of anything else, but everything else is dependent on Him, because everything in heaven and on earth is created by Him and is enslaved by Him; none of them could move even an atom's weight except with His permission. If all the people of heaven and earth were to come together to create a fly, they would not be able to do so.

Allah says:

وَأَنَّ اللَّهَ هُوَ الْعَلِيُّ الْكَبِيرُ

and that Allah, He is the Most High, the Most Great.

meaning, He is the Most High and there is none higher than Him, and He is the Most Great Who is greater than everything. Everything is subjugated and insignificant in comparison to Him