What is meant by "his sensual desire" in the Sacred Hadith about fasting: "He gives up his food, his drink, and his sensual desire for My sake"? And does it mean abstaining from every sensual desire except what is permitted by text, such as kissing one's wife, or is it an absolute word that requires specification, such as sexual intercourse, and everything else is permissible?

Kissing one's wife while fasting involves details. The "desire" mentioned in the Hadith (definition) is said to refer to the desire for intercourse, and it is also said to be general, encompassing every desire. However, what invalidates the fast among these is the intentional desire for intercourse, food, and drink. It has been explicitly stated in multiple narrations that what is intended is abstaining from food, drink, and intercourse. Among the desires that also invalidate the fast is masturbation, by intentionally expelling semen.