What is the limit at which sexual thoughts become reprehensible and depart from the natural inclination, and by condemning them, does Ibn al-Qayyim mean intending them or their frequent occurrence to the mind?

Ibn al-Qayyim held that the preservation of faith is achieved by controlling moments, passing thoughts (khatarat), utterances, and steps, as sins enter through these very doors. Passing thoughts are the origin of good and evil, and from them wills are generated. However, the mere occurrence of a passing thought does not cause harm unless it is invited and engaged with. Scholars have agreed that passing thoughts and self-talk are pardoned as long as they do not become settled. Ibn al-Qayyim stated that passing thoughts and ideas are the origin of all knowledge and action, and that repelling them at their inception is easier than severing them once they have gained strength. Therefore, what is required is to resist evil passing thoughts and not to yield to them, for resisting them strengthens faith and elevates one's rank.