What constitutes incapacitating harm preventing the obligation of Jihad?

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Freedom from harm means being safe from blindness (A'ma), lameness (Arj), and severe illness (Marad), as evidenced by the verse: 'There is no blame upon the blind nor upon the lame nor upon the sick...' (Quran 21:61). Blindness is a clear impediment. Lameness that prevents proper walking and riding, such as a major disability (Zamaanah), prohibits Jihad. Minor lameness allowing riding or walking, though hindering rapid pursuit, does not prohibit obligation, analogous to the one-eyed person (A'war). Similarly, only severe illness that prevents the possibility of Jihad is prohibitive; minor ailments like a toothache or light headache do not prevent obligation since Jihad remains possible for the afflicted, similar to the one-eyed person.