פירוש על דברים 23:3

לא יבא ממזר בקהל ה׳ ONE BORN IN INCEST OR ADULTERY SHALL NOT COME INTO THE ASSEMBLY OF THE LORD — i.e. he shall not marry an Israelite woman (Yevamot 78b).

MAMZEIR’ (BASTARD). The term signifies a man who is muzar (estranged) from his brothers and his friends, for it is not known whence he comes. This is similar to the verse, And a ‘mamzeir’ shall dwell in Ashdod, and I will cut off the pride of the Philistines,²²³Zechariah 9:6. the verse stating that no one will dwell in Ashdod save a foreigner or a stranger who will chance to pass by, for the pride of the Philistines will have been cut off from it [Ashdod]. Now, if a child is born to a man from his father’s wife, he [the father] will put him far away and not acknowledge him because of his shame and disgrace [resulting] from the evil deed that he committed. His mother also will cast him away by night, like the asufi (any cast-off child whose father and mother are unknown) that is mentioned in the Talmud.²²⁴Kiddushin 69a. Thus the mamzeir is “estranged” in his native city, and so also the offspring of any of the forbidden relations as our Rabbis have said in Yerushalmi Kiddushin:²²⁵Yerushalmi Kiddushin III. 14. “Rabbi Abahu said: What is the meaning of mamzeir? Mum zar (a strange blemish”).

ממזר, “bastard,” according to Nachmanides the term is derived from מוזר, something or somebody strange, not fitting into an accepted mould and therefore excluded, rejected. When a man fathers the child of his father’s wife, he is so ashamed that he will not acknowledge the child, will shun it, ostracise it; he will try to minimize his own shame by not being associated with the product of his unbridled lust. Similarly, the mother of such a child will try and rid herself of it in the dark of the night. The child will wind up being a “foundling.”