[If] a man fell into water, whether all its shores are in sight or not, his wife is prohibited. R' Meir said: There was [once] an incident where someone fell into a large well and surfaced after three days. R' Yose said: There was [once] an incident where a blind man descended into a cave to immerse himself, and was followed by his guide; they remained [undetected] long enough from them to have died, and [the Rabbis] permitted their wives to remarry. There was another incident at Asya, where someone was lowered into the sea and they recovered nothing but his leg. The Sages said: [If the leg was severed] above the knee, she may remarry; [if the leg was] below the knee, she may not remarry.

Even if he heard women saying, “So-and-so died,” it is sufficient. R' Yehudah says: Even if he heard children saying, “We are going to eulogize and bury so-and-so.” [His testimony is valid] whether he intends [to testify] or not. R' Yehudah ben Bava says: A Jew's [testimony is valid], even if he intended [to testify], but [if] a non-Jew intended [to testify], his testimony is not valid.

Witnesses may testify [even if they saw] by lamplight and moonlight, and we permit remarriage on the basis of a voice. There was [once] an incident where someone stood on a hilltop and said, “So-and-so, the son of so-and-so, from such and such a place, has died,” They went [to the hilltop] but found no one there, [yet] they permitted his wife to remarry. There was another incident at Zalmon where someone said, “I am so-and-so, the son of so-and-so. A snake has bitten me, and I am dying.” They went [there] but could not recognize him, [yet] they permitted his wife to remarry.

R' Akiva said: When I went down to Nehardea to fix the leap year, I encountered Nechemiah of Beis Deli. He said to me, “I have heard that in Eretz Yisrael they do not permit a woman to remarry by the testimony of a single witness, except for R' Yehudah ben Bava.” I said to him: “This is correct.” He said to me: “Tell them in my name: You know that the country is in turmoil because of ravaging troops. I have a tradition from Rabban Gamliel the Elder that we permit a woman to remarry by the testimony of a single witness.” When I came and presented the matter before Rabban Gamliel, he rejoiced at my words, and said, “We have found a companion for R' Yehudah ben Bava.” As a result of the exchange, Rabban Gamliel recalled that [some] men had [once] been killed in Tel Arza, and Rabban Gamliel [the Elder] had permitted their wives to remarry on the testimony of a single witness. [It [then] became established to permit remarriage on the testimony of a single witness;] and it became established to permit remarriage on [the testimony of] one witness quoting another, and on the testimony of a slave, a woman, and a slavewoman. R' Eliezer and R' Yehoshua say: We do not permit a woman to remarry by the testimony of a single witness. R' Akiva says: Not by the testimony of a woman, [a slave, a slave-woman,] or relatives. They said to him: There was [once] an incident where some Leviim journeyed to Zoar, the city of date palms, and one of them fell ill during the journey, and they brought him to an inn. On their return [trip], they said to the woman innkeeper, “Where is our companion?” She said to them, “He died and I buried him” —- and they permitted his wife to remarry. They said to him: Shouldn't the wife of a Kohen be as [good as] a woman innkeeper? He replied: When the woman innkeeper is believed. This woman innkeeper brought out to them his staff, his baggage, and the Torah scroll in his possession.