refers to drawing water into the nostrils during wuḍūʾ, except when you are fasting. In that case do not overdo the inhalation, for if you inhale forcefully the water may reach your stomach through the nose. This shows that food or drink reaching the stomach by way of the nose nullifies the fast just as if it entered through the mouth.

As for injections—whether into a vein, the hand, the back, or anywhere else—they do not break the fast unless they are nutrient drips that substitute for eating and drinking. Such nutritive injections do invalidate the fast, and it is unlawful for someone observing an obligatory fast to use them except in cases of real need or dire necessity. If he is compelled to take them, he should break his fast, receive the injection, and later make up that day.

The author then cites the ḥadiths of ʿĀʾishah and Umm Salamah (may Allah be pleased with them), stating that the Prophet ﷺ would enter the morning in a state of major ritual impurity and still fast, performing the full bath afterward. This is likewise permissible: a person in the state of janābah may intend to fast even if he does not bathe until after dawn, exactly as the Prophet ﷺ did. The report of ʿĀʾishah and Umm Salamah is proof that the Prophet’s actions carry legal weight; one must not claim that they were unique to him, for the basic rule is that there is no specificity. Whatever the Prophet ﷺ does is truth: if it is an act of worship, it is worship; if it is a customary matter, it remains a custom and is not forbidden. Allah alone grants success.