Shaykh Taqī al-Dīn Ibn Taymiyyah said to him:

His words, “Allah has permitted trade,” are immediately followed by His words, “and forbidden usury.” Most forms of usury are also called sales. If “usury” is an indeterminate term, then its meaning is unknown. Excluding something unknown from something known entails uncertainty about what is excluded. Thus, what is intended remains the permissibility of sales that are not usury. Unless a particular transaction is established not to be usury, it cannot validly be included among lawful sales. This precludes claiming general applicability. If, on the other hand, “usury” is a general term, it is still excepted from sales. The term “sale” therefore remains restricted in scope, and one cannot validly claim that it applies generally without qualification.

Ibn al-Murahhal said:

“This is a case of restriction. Here, two general statements conflict; it is not a case of exception, for the forms used to express exceptions are well known. If this is a restriction, it does not preclude claiming general applicability for the expression.”

Shaykh Taqī al-Dīn said:

“This is a connected statement whose parts are linked together, and it is a case of restriction by an attached qualification. Jurists call this an exception, as when someone says, ‘This house belongs to him, and this room within it belongs to me.’ This is equivalent to saying, ‘except this room.’ Likewise, if someone says, ‘Honor these people, and do not honor so-and-so,’ when that person is one of them, this is equivalent to saying, ‘except so-and-so.’ That being so, it amounts to saying, ‘Allah has permitted trade except that which constitutes usury.’”