The Quran

وَما قَدَرُوا اللَّهَ حَقَّ قَدرِهِ وَالأَرضُ جَميعًا قَبضَتُهُ يَومَ القِيامَةِ وَالسَّماواتُ مَطوِيّاتٌ بِيَمينِهِ ۚ سُبحانَهُ وَتَعالىٰ عَمّا يُشرِكونَ

Muhammad Asad

And no true understanding of God have they [who worship aught beside Him], inasmuch as the whole of the earth will be as a [mere] handful to Him on Resurrection Day, and the heavens will be rolled up in His right hand:¹ limitless is He in His glory, and sublimely exalted above anything to which they may ascribe a share in His divinity!

I.e., the whole universe is as nothing before Him: for this specific allegory of God's almightiness, see 21:104. There are many instances, in the Qur'an as well as in authentic ahadith, of the clearly metaphorical use of the term "hand" in allusions to God's absolute power and dominion. The particular reference, in the above, to the Day of Resurrection is due to the fact that it will be only on his own resurrection that a human being shall fully grasp the concept of God's almightiness; referred to in the subsequent words, "limitless is He in His glory" (subhanahu)".