It is well known, that if one speaks lashon horah about his friend, he receives all his friends aveiros, and his friend in turn receives all of the ba’al lashon horah’s mitzvos. The concept is mentioned by the Chovos HaLevovos (Sha’ar Hachniah, Perek 7). What happens if one speaks lashon horah about his friend, and then he does teshuva, does he get his mitzvos back?
It is brought down from R’ Chaim Kanievsky (Derech Sicha, Vol 2, pg. 287) that if one does teshuva he certainly gets his mitzvos and merits back. R’ Chaim adds, that presumably once the averios left the one who lashon horah was spoken about, they don’t return.
In a case when teshuva wasn’t done, however, they were mochel each other, it may well be that things go back to how they were before the lashon horah was spoken, tzorich iyun.
