Refutation of false accusations against the Prophet

وَمَا يَنۢبَغِى لَهُمْ وَمَا يَسْتَطِيعُونَ

It is not allowable for them, nor would they be able.

أَمْ تَسْـَٔلُهُمْ أَجْرًا فَهُم مِّن مَّغْرَمٍ مُّثْقَلُونَ

Or do you ask of them a payment, so they are by debt burdened down?