How was al-'Ara'ya permitted, given that it is forbidden, for the sake of pressing need rather than dire necessity?

Question : How was al-'Ara'ya permitted, given that it is forbidden, for the sake of pressing need rather than dire necessity? The scholars' rule is that a forbidden thing is not permissible except for dire necessity, based on the saying of Allah the Exalted and the saying of the Prophet (peace and blessings be upon him):

Answer : There are two types of forbidden things: those forbidden in themselves and those forbidden for the sake of something else. Al-'Ara'ya was permitted for pressing need, although its permissibility requires specific conditions; it is not an absolute permissibility. It was permitted for pressing need because the original prohibition of riba al-fadl (usury of excess in a like-for-like exchange) was to prevent it from becoming a means to riba al-nasi'ah (usury of deferment). This is why it came in the hadith: meaning that the true riba intended is riba al-nasi'ah. Riba al-fadl, where one sells a sa' (a dry measure of about 3 kg) for two sa's, becomes a means to deferment; it becomes a means to deferment. The point is that if an increase is permitted for the sake of delivery, the mind shifts to the permissibility of an increase for the sake of delay, and one falls into riba al-nasi'ah. And what is forbidden for the sake of something else is permitted by pressing need. From this, a small amount of silver is permitted if a vessel cracks or breaks, to condition it with some silver, even though it is a dire necessity where one could condition it with something else. But since this falls under the prohibition of means and is not forbidden in itself, the matter is relaxed in it. Did you understand? Even though al-'Ara'ya must be by estimation (kharv), must not exceed five wasq, and there must be a pressing need.