Bamidbar Rabbah (19:03) On what account is a leper cleansed with the aid of the tallest of tall trees and with the lowest of low ones, namely, with the cedar tree and the hyssop? He had been punished with leprosy owing to his having exalted himself like the cedar tree. Having humbled himself like the hyssop he was healed by the aid of a hyssop.
Birchas Asher (Vayikra13:01) According to those who agree with the view of Rambam one can ask from the words of the gemora that there is no tzuras in Babylonia because they eat beets, drink beer, and bathe in the waters of the Euphrates.\that means that Tzuras is physiological In contrast there is a medrash about turas of houses in which it was a sign from God to find hidden treasure. Thus we see that our Sages were not in agreement about this and there are conflicting views
Kesubos (77b) Rabbi Yoḥanan said: For what reason are there no lepers in Babylonia? Because they eat beets, drink beer, and bathe in the waters of the Euphrates, all of which are good for the body. It is prohibited to go four cubits to the east of a leper. R. Simeon b. Lakish said: Even a hundred cubits. They did not really differ; the one who said four cubits referred to a time when there is no wind blowing, whereas the one who said not even a hundred cubits, eferred to a time when a wind is blowing. R. Meir would not eat eggs that came from an alley of lepers. R. Ammi and R. Assi would not enter a leper's alley. Resh Lakish, when he saw one of them in the city, threw stones towards him, and said: ' Go to your place, and do not defile other people,’ as R. Hiyya taught: He shall dwell alone of them, hid himself from him,
Magen Avraham (O.C. 173:1): The combination causes leprosy – It is possible that in modern times there is not so much danger because we know that many things that are mentioned in the Talmud as being a danger because of ruach rah and other reasons do not cause harm today because nature has changed. Also it is a function of the nature of the particular country…
Moreh Nevuchim (03:47) Tzaraas is a miracle received in our nation by tradition, in the same manner as the effect of the trial of a faithless wife. The good effect of this belief is evident. Leprosy is besides a contagious disease, and people almost naturally abhor it, and keep away from it.
Ralbag (Vayikra 13:47) Tzara’as on these objects is caused by moisture and heat… this causes them to be damaged and destroyed… the discoloration is what you’d find in moldy places, like water near a dump, where things turn green or red.
Ramban (Vayikra 13:47) AND WHEN THE PLAGUE OF LEPROSY IS IN A GARMENT. This is not in the natural order of things, nor does it ever happen in the world outside Israel, and similarly leprosy of houses is not a natural phenomenon. But when Israel is wholly devoted to G-d, then His spirit is upon them always, to maintain their bodies, clothes and houses in a good appearance. Thus as soon as one of them commits a sin or transgression, a deformity appears in his flesh, or on his garment, or in his house, revealing that G-d has turned aside from him…
Vayikra Rabbah (17:03) For ten sins does leprosy come upon the world: (i) idol-worship, (ii) gross unchastity, (iii) bloodshed, (iv) the profanation of the Divine Name, (v) blasphemy of the Divine Name, (vi) robbing the public, (vii) usurping [a dignity] to which one has no right, (viii) overweening pride, (ix) evil speech, and (x) an evil eye.
Vayikra Rabbah (17:06) When the Canaanites heard that the Israelites were approaching, they set to and hid their valuables in the houses and in the fields. Said G-d: ' I promised the Israelitesforefathers that I would bring their children into a land full of all that is good, as it is said, And houses full of all good things. What did G-d do?-He brought plagues upon a house

