Al-Qalam - 68:46

أَمْ تَسْأَلُهُمْ أَجْرًا فَهُم مِّن مَّغْرَمٍ مُّثْقَلُونَ
[68:46]
Or do you ask from them a reward, so that they are burdened with debt?
Or is it that thou dost ask them for a reward, so that they are burdened with a load of debt?-
Or dost thou (Muhammad) ask a fee from them so that they are heavily taxed?