الفرار من المجذوم
Direct guidance to keep physical distance from a person with leprosy, framed alongside the general principle that disease does not spread except by Allah's permission.
فِرَّ مِنَ الْمَجْذُومِ كَمَا تَفِرُّ مِنَ الْأَسَدِ
“Flee from the leper as you would flee from a lion.” (meaning, not a literal translation)
Elsewhere the Prophet ﷺ is reported to have taken a leprous man's hand and eaten with him, which scholars read as demonstrating that the general precaution does not require ostracizing or humiliating the afflicted person — the two reports are generally reconciled as addressing different situations (routine avoidance of exposure vs. an act of specific compassion and de-stigmatization) rather than contradicting each other.
Classical commentators reconcile this with hadith negating 'contagion' by reading both as true: transmission occurs only by Allah's decree, and He has ordinarily made prevention part of that decree — so avoiding exposure is both prudent and theologically consistent. Ibn al-Qayyim discusses this tension directly, treating practical precaution and belief in Allah's ultimate causation as complementary rather than in conflict.
Modern medicine confirms leprosy (Hansen's disease) does spread through prolonged close contact, though it's far less contagious than historically feared and highly treatable with modern multidrug therapy — current medical understanding sits between the two poles of 'completely untransmissible' and 'as dangerous as historically assumed.'