A woman whose husband and son went overseas, and they came and told her, “Your husband died, and then your son,” and she married, and afterward they told her that the reverse had occurred —- she must leave [her husband], and any child [born] before or after is a mamzer.  [If] they told her, “Your son died, and then your husband,” and she underwent yibum, and afterward they told her that the reverse had occurred —- she must leave [her husband], and any child [born] before or after is a mamzer.  [If] they told her, “Your husband died,” and she married, and afterward they told her, “He was alive then but is now dead” —- she must leave [her husband], and any child [born] before is a mamzer, but [a child born] after is not a mamzer.  [If] they told her, “Your husband died,” and she was [then] betrothed, and then her husband reappeared —- she may return to him; even if the last one gave her a bill of divorce, he does not disqualify her from the priesthood. R' Elazar ben Masya expounded the following: “... a woman divorced from her husband ...” (Leviticus 21:7) but not [a woman divorced] from a man who is not her husband.