The Cattle
قُل لِّمَن مَّا فِى ٱلسَّمَـٰوَٰتِ وَٱلْأَرْضِ ۖ قُل لِّلَّهِ ۚ كَتَبَ عَلَىٰ نَفْسِهِ ٱلرَّحْمَةَ ۚ لَيَجْمَعَنَّكُمْ إِلَىٰ يَوْمِ ٱلْقِيَـٰمَةِ لَا رَيْبَ فِيهِ ۚ ٱلَّذِينَ خَسِرُوٓا۟ أَنفُسَهُمْ فَهُمْ لَا يُؤْمِنُونَ
Say, "To whom belongs whatever is in the heavens and earth?" Say, "To Allah." He has decreed upon Himself mercy. He will surely assemble you for the Day of Resurrection, about which there is no doubt. Those who will lose themselves [that Day] do not believe.
Nearby ayahs help place verse 6:12 in sequence and meaning.
وَلَقَدِ ٱسْتُهْزِئَ بِرُسُلٍ مِّن قَبْلِكَ فَحَاقَ بِٱلَّذِينَ سَخِرُوا۟ مِنْهُم مَّا كَانُوا۟ بِهِۦ يَسْتَهْزِءُونَ
And already were messengers ridiculed before you, but those who mocked them were enveloped by that which they used to ridicule.
قُلْ سِيرُوا۟ فِى ٱلْأَرْضِ ثُمَّ ٱنظُرُوا۟ كَيْفَ كَانَ عَـٰقِبَةُ ٱلْمُكَذِّبِينَ
Say, "Travel through the land; then observe how was the end of the deniers."
۞ وَلَهُۥ مَا سَكَنَ فِى ٱلَّيْلِ وَٱلنَّهَارِ ۚ وَهُوَ ٱلسَّمِيعُ ٱلْعَلِيمُ
And to Him belongs that which reposes by night and by day, and He is the Hearing, the Knowing.
قُلْ أَغَيْرَ ٱللَّهِ أَتَّخِذُ وَلِيًّا فَاطِرِ ٱلسَّمَـٰوَٰتِ وَٱلْأَرْضِ وَهُوَ يُطْعِمُ وَلَا يُطْعَمُ ۗ قُلْ إِنِّىٓ أُمِرْتُ أَنْ أَكُونَ أَوَّلَ مَنْ أَسْلَمَ ۖ وَلَا تَكُونَنَّ مِنَ ٱلْمُشْرِكِينَ
Say, "Is it other than Allah I should take as a protector, Creator of the heavens and the earth, while it is He who feeds and is not fed?" Say, [O Muhammad], "Indeed, I have been commanded to be the first [among you] who submit [to Allah] and [was commanded], 'Do not ever be of the polytheists.' "