in cases of necessity. Some say:

“What is forbidden has been made permissible despite the continued presence of the cause that prohibits it, namely its properties as nourishment.”

Others say:

“Necessity has not removed the ruling arising from the cause—namely prohibition—by removing its capacity to entail prohibition. Thus, nothing prohibiting remains in this situation, since prohibition cannot cease while its fully sufficient cause remains.”

The dispute can be resolved as follows: if “the prohibiting cause” means the fully sufficient cause, which necessarily entails prohibition, then this ceases to exist in a situation of dire hunger. For something cannot exist without that which necessarily follows from it. Permissibility is established in this situation, so the cause that necessarily entails prohibition cannot be present. If, however, “cause” means that which would entail prohibition were it not for an overriding countervailing factor, then this undoubtedly exists when prohibition applies. But the overriding countervailing factor has removed its capacity to entail prohibition, so it no longer entails prohibition in this situation. If the dire hunger is assumed to cease, the cause resumes its effect because the factor opposing it has ceased.

The same reasoning applies to whether dry ablution removes ritual impurity or not, for this depends on the position of those who say that it removes ritual impurity. Once it becomes clear to someone holding this position that it removes ritual impurity temporarily, until one is able to use water, whereupon the impurity returns, this meaning is not impossible. The revealed law has indicated it by making earth a means of purification. Water serves as a means of purification when it removes ritual impurity; otherwise, while major ritual impurity remains