He—may Allah have mercy on him—was asked:

About rinsing the mouth, drawing water into the nose, using a tooth-stick, tasting food, vomiting, bleeding, applying oil, and applying kohl.

He replied:

Rinsing the mouth and drawing water into the nose are prescribed for the fasting person by scholarly consensus. The Prophet, peace and blessings be upon him, and the Companions used to rinse their mouths and draw water into their noses while fasting. However, he said to Laqīt ibn Sabira:

“Draw water thoroughly into your nose, unless you are fasting.”

Thus, he prohibited doing so excessively, not drawing water into the nose itself.

Using a tooth-stick is permissible without dispute. However, scholars differed over whether it is disliked after the sun passes its zenith, holding two well-known opinions, both transmitted from Ahmad. No evidence from Islamic law establishes that it is disliked in a way that would warrant restricting the general scope of the texts concerning the tooth-stick. Drawing an analogy between it and a martyr’s blood, or similar matters, is weak on several grounds, as explained at length elsewhere.

Tasting food without a need is disliked, but it does not invalidate one’s fast. As for tasting it when there is a need,