The Gemara brings that if one has a tree whose fruits fall off quickly before ripening, a person is permitted to load it up with stones and mark it with a red mark; it is not included in the customs of non-Jews. The stones are meant to weaken the tree’s strength from its quickness of shedding fruits, and the red mark is for people to notice and daven that it should return to being healthy and fruitful. This is derived from a leper about whom the Torah states וטמא טמא יקרא, he should let people know about his painful situation in order that they should daven for him to become healed.
The Iyun Yaakov explains that in order for the leper to be healed he specifically needs someone other than himself to daven for him. Although Chazal teach that a sick person who davens for himself is answered first, before anyone else who davens for him, a leper is an exception. His own davening will not help at all, since Hashem will not accept it. We see this from when Miriam became a leper; the Torah states Moshe davened for her to be healed. It was not sufficient for Miriam to daven for herself, others had to daven for her.
The Gemara brings that burial-plots are supposed to be marked so Kohanim who eat teruma should not become tamei. This is derived from a leper as the passuk states וטמא טמא יקרא, which Rashi explains that a leper announces that he is tamei so that people should separate from him. So too by marking burial-plots it notifies people to stay away. The Maharsha highlights that this a second lesson learned from these words.
Onkelos translates וטמא טמא יקרא differently, “he shall call out ‘and do not become tamei and do not become tamei.’” The Nefesh HaGer explains Onkelos translates the intent; the leper should warn people to stay away from him so that they should not become tamei. The Nesina LaGer explains that Onkelos understands the leper does not actually call out the word טמא about himself, rather he says “don’t become tamei,” separate from here. So too the Toras Kohanim brings that a leper says the word “פרוש separate” which Rabbeinu Hillel explains is in order that they should not touch him. This is as the Gemara teaches: the Torah doesn’t say the lashon טמא defiled, rather changes to איננה טהרה not pure (Parshas Noach), so as not to say something which is not nice.
A מצורע is a leper, and צרעת is leprosy. Onkelos translates both of these words with the lashon סגר meaning to close. The Me’at Tzari explains this hints to a leper who is closed in a house and his door is closed, and is not seen until the end of the week. Harav Yonason Ibishitz explains סגר hints that since he spoke lashon harah, his davening will not be answered. The Me’at Tzari adds the gateways of heaven will not allow his davening to pass through, they are sealed shut for him.
Let us all daven for each other’s health and success, and may Hashem answer our tefillos!