Surah Ash-Shu'ara 26:24

قَالَ رَبُّ ٱلسَّمَـٰوَٰتِ وَٱلْأَرْضِ وَمَا بَيْنَهُمَآ ۖ إِن كُنتُم مُّوقِنِينَ

[Moses] said, "The Lord of the heavens and earth and that between them, if you should be convinced."

Translation: Saheeh International

Tafsir

He said ‘The Lord of the heavens and the earth and all that is between them in other words the Creator of all that — should you have conviction’ that He exalted be He is their Creator then believe in Him alone.

Excerpt from Tafsir al-Jalalayn, commentary on 26:24, via Quran.com. The reader has the full commentary and 9 more tafsirs.