عَلَىٰٓ أَن نُّبَدِّلَ خَيْرًا مِّنْهُمْ وَمَا نَحْنُ بِمَسْبُوقِينَ
'Alaaa an nubaddila khairam minhum wa maa Nahnu bimasbooqeen
to replace them with better than them — and we cannot be outrun.
Khayran minhum distinguishes this warning from its parallels elsewhere, which speak of bringing others, or of a fresh creation, without ranking them against anyone. Here the replacements would be better, which makes the threat comparative and personal rather than a matter of numbers. Masbūqīn belongs to the racing field, the runner who is overtaken, and the very next line tells the Prophet to leave them be, so the power just claimed goes deliberately unused.