Does a person's feeling of distress over forgetting a Mushaf (copy of the Qur'an) they habitually carried, or a specific calculator in exams, count as bad omen (tashā'um) or ill-prediction (ṭīrah)? And what is the difference between feeling distressed and bad omen (ṭīrah) and ill-prediction (tashā'um)?

Shortness of breath from forgetting something is not a forbidden ṭīrah (superstitious belief, ill omen), for ṭīrah is pessimism about something that hinders one's intentions, and the Sharʿ (Islamic law) has rejected and invalidated it. The criterion for forbidden ṭīrah is that which compels one to proceed or to desist, as stated in the ḥadīth: "Indeed, ṭīrah is only that which makes you go forth or holds you back." So, if forgetting does not cause a person to desist from their affair, then they are not considered to be practicing ṭīrah or being pessimistic.