قُلِ ٱللَّهُمَّ فَاطِرَ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ عَٰلِمَ ٱلْغَيْبِ وَٱلشَّهَٰدَةِ أَنتَ تَحْكُمُ بَيْنَ عِبَادِكَ فِى مَا كَانُوا۟ فِيهِ يَخْتَلِفُونَ
"Say: 'O God! Originator of the heavens and the earth, Knower of the seen and the unseen! It is You who will judge between Your servants in the matters over which they differed.'"
فَاطِر — root ف-ط-ر: to split open, to bring forth for the first time. The lexicographers record together the branches of the root for "breaking a fast" (ifṭār) and "being split open" (infiṭār). The root was treated in al-Infiṭār; I rely on that treatment.
That the verse is built as a prayer is worth recording: the matter disputed throughout the sūra — disagreement — is here taken out of dispute and its ruling deferred, and this matches the sentence in the third verse: inna'llāha yaḥkumu baynahum fī mā hum fīhi yakhtalifūn. The same expression twice: once as a statement, once as a prayer.
وَلَوْ أَنَّ لِلَّذِينَ ظَلَمُوا۟ مَا فِى ٱلْأَرْضِ جَمِيعًا وَمِثْلَهُۥ مَعَهُۥ لَٱفْتَدَوْا۟ بِهِۦ — "if all that is in the earth were theirs, and as much again with it, they would offer it all as ransom to escape the punishment."
The measure must be recorded: the whole of the earth and as much again. That is, a quantity that goes beyond what exists. And even so it is not accepted.
وَحَاقَ بِهِم مَّا كَانُوا۟ بِهِۦ يَسْتَهْزِءُونَ — the root ح-ي-ق was treated in Ghāfir (al-Muʾmin) at 40/45: a snare turning back on the one who set it and closing around him. Here what closes around them is the very thing they made an object of mockery.