﴿ وَلَمَّا بَلَغَ أَشُدَّهُۥٓ ءَاتَيْنَٰهُ حُكْمًۭا وَعِلْمًۭا ۚ وَكَذَٰلِكَ نَجْزِى ٱلْمُحْسِنِينَ ﴾

“And when he reached full manhood, We bestowed upon him the ability to judge [between right and wrong], as well as [innate] knowledge: for thus do We reward the doers of good.”

And when he reached his prime — which was at 30 or 33 years of age — We gave him power of judgement wisdom and knowledge understanding in matters of religion before his call to prophethood. Thus just as We rewarded him We reward those who are virtuous to the good of their souls.