﴿ ۞ إِنَّ ٱللَّهَ يُمْسِكُ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضَ أَن تَزُولَا ۚ وَلَئِن زَالَتَآ إِنْ أَمْسَكَهُمَا مِنْ أَحَدٍۢ مِّنۢ بَعْدِهِۦٓ ۚ إِنَّهُۥ كَانَ حَلِيمًا غَفُورًۭا ﴾

“Verily, it is God [alone] who upholds the celestial bodies and the earth, lest they deviate [from their orbits] - for if they should ever deviate, there is none that could uphold them after He will have ceased to do so. [But,] verily, He is ever-forbearing, much-for­giving!”

Truly God sustains the heavens and the earth lest they disappear in other words He prevents them from disappearing. And if wa-la-in the lām is for oaths they were to disappear there is none that can sustain them after Him in other words other than Him. Truly He is ever Forbearing Forgiving in deferring the punishment of the disbelievers.