"the third generation": I might think that both the second and the third generation are forbidden; it is, therefore, written "the third generation (shall come for them into the congregation of the L-rd.") R. Yehudah said: Minyamin, an Egyptian proselyte, was a friend of mine of the disciples of R. Akiva, and he said to me: I am an Egyptian proselyte married to an Egyptian proselytess, and I am going to marry my son to the daughter of an Egyptian proselytess, so that my grandson will be fit to enter the congregation (of Israel) in fulfillment of "the third generation shall come, etc."