Rational argumentation and empirical observation as proofs

قُلْ سِيرُوا۟ فِى ٱلْأَرْضِ ثُمَّ ٱنظُرُوا۟ كَيْفَ كَانَ عَـٰقِبَةُ ٱلْمُكَذِّبِينَ

Say, "Travel through the land; then observe how was the end of the deniers."