The state of being born out of lawful wedlock; in Jewish law, the state of being born of any of the marriages prohibited in the Bible and for which the punishment is excision ("karet"; Yeb. 49a; Maimonides, "Yad," Issure Biah, 15:1). The exception to this rule is the child born of relations with a woman during her period of uncleanliness, in which case, although the punishment for such a transgression is excision, the child is not considered illegitimate (see See BASTARD; ḤALALAH).
Three kinds of illegitimates ("mamzer") are recognized in Jewish law; namely:
A child born of an unmarried woman ("penuyah") is considered only a doubtful mamzer, even if the mother admits that she has had relations with a mamzer and the alleged father also admits the fact. If, however, the mother says that she has had intercourse with an Israelite ("kasher"), even though the latter does not admit it, the child is legitimate. He may not, however, marry into the alleged father's family, and he can not claim inheritance in the estate, unless the alleged father admits the paternity. The child of a betrothed woman is legitimate if she claims that the child is by her betrothed husband, and if he does not refute her. In such a case the child is also entitled to a share in the alleged father's estate. If, however, the alleged father denies the paternity, the child is considered a mamzer (Shulḥan 'Aruk, Eben ha-'Ezer, 4, 26, 27).
The children of illegitimates are also considered illegitimates, whether both parents are illegitimates or only one of them is an Israelite. The mother's testimony concerning the illegitimacy of her child is not admitted in evidence, and the father is believed with regard to his child only if that child has not yet any children of his own (Ḳid. 78b). A man's testimony against himself is believed in so far as to disqualify him or his children from marrying an Israelitish woman; but it does not permit him to marry an illegitimate ("mamzeret") until he produces confirmatory testimony. If he has grandchildren, his testimony is admitted in evidence only with regard to himself; he can not place the stigma on his family. ELIJAH; FOUNDLING; MESSIAH.