Mischna zu Bamidbar 26:54

Rabbi Eliezer ben Yaakov says: a woman who is a daughter of a convert may not marry a priest unless her mother was herself an Israelite. [This law applies equally to the offspring] whether of proselytes or freed slaves, even to ten generations, unless their mother is an Israelite. A guardian, an agent, a slave, a woman, one of doubtful sex, or a hermaphrodite bring the bikkurim, but do not recite, since they cannot say: “Which you, O Lord, have given to me” (Deuteronomy 26:10).