Does the husband's statement to his wife, "By Allah, I no longer long for you," count as an idle oath if he only meant by it that he no longer longs for her physically?

Lapse of an oath (laghw al-yameen) occurs when the one taking the oath utters it unintentionally. If what transpired from the husband was of this nature, then there is nothing upon him.

However, if he intended the oath, then if he was truthful, that is one thing; otherwise, it is a ghamosh oath (a false oath sworn deliberately to usurp another's right).

A Muslim should guard his tongue from excessive oath-taking and should only swear when there is a need and when he is truthful.

Sexual intimacy is a right of the wife upon her husband, and he must provide it to her according to her desire and his ability. He is not permitted to withhold it from her except for a legitimate Shar'i (Islamic legal) excuse.