وَما أَفاءَ اللَّهُ عَلىٰ رَسولِهِ مِنهُم فَما أَوجَفتُم عَلَيهِ مِن خَيلٍ وَلا رِكابٍ وَلـٰكِنَّ اللَّهَ يُسَلِّطُ رُسُلَهُ عَلىٰ مَن يَشاءُ ۚ وَاللَّهُ عَلىٰ كُلِّ شَيءٍ قَديرٌ

The gains that God granted His Messenger from them, without you having to mount on horses or camels, are because God gives His messengers authority over whomever He wills. God has power over all things.