Human weakness and doubt despite clear commands

قَالُوا۟ ٱدْعُ لَنَا رَبَّكَ يُبَيِّن لَّنَا مَا هِىَ إِنَّ ٱلْبَقَرَ تَشَـٰبَهَ عَلَيْنَا وَإِنَّآ إِن شَآءَ ٱللَّهُ لَمُهْتَدُونَ

They said, "Call upon your Lord to make clear to us what it is. Indeed, [all] cows look alike to us. And indeed we, if Allāh wills, will be guided."