Nedarim

R. Elai said in the name of Rab. If [a Rabbi] places a person under a ban in his presence, the ban can be revoked only in his presence; if in his absence, it can be revoked both in his presence and in his absence. R. Hanin said in Rab's name. One who hears his neighbour utter God's name in vain  must place him under a ban; otherwise he himself must be under a ban,  because the unnecessary utterance of the Divine Name always leads to poverty, and poverty leads to death, as it is written, [And the Lord said unto Moses in Midian, Go, return unto Egypt]. For all the men are dead [which sought thy life];  and it was taught: Wherever the Sages cast their eyes [in disapproval] death or poverty has resulted. R. Abba said: I was standing in the presence of R. Huna, when he heard a woman utter God's name in vain. Thereupon he banned her, but immediately lifted the ban in her presence. This proves three things: [i] He who hears his neighbour utter the Divine Name unnecessarily must excommunicate him; [ii] If [a Rabbi] bans a person in his presence, the ban must be lifted in his presence too. [iii] No time need elapse between the imposition and the lifting of a ban. R. Giddal said in Rab's name: A scholar may utter a ban against himself, and lift it himself. But is this not obvious? — I would think that a prisoner cannot free himself from prison; hence we are taught otherwise. Now, how can such a thing occur? — As in the case of Mar Zutra the Pious:  when a disciple incurred a ban,  [Mar Zutra] first excommunicated himself and then the disciple.  On arriving home, he lifted the ban from himself and then from the disciple. R. Giddal also said in Rab's name: