A Son's tribe is determined by the father - Key Passages
The tribe of a son is always established by the tribe of the father. If one is a Jew or not is decided by the mother. Below are a few of the passages that show that the father decides the tribe. Numbers 1:2 Take the sum of all the congregation of the children of Israel, by families following their fathers' houses ; Numbers 1:16 These were the ones summoned by the congregation, the princes of the tribes of their fathers ; they are the heads of the thousands of Israel. Numbers 1:18 and they assembled all the congregation on the first day of the second month, and they declared their pedigrees according to their families according to their fathers' houses ; according to the number of names, a head count of every male from twenty years old and upward. Numbers 1:20 This was [the sum of] the children of Reuben, the firstborn of Israel, their descendants according to their families, according to their fathers' houses; the number of individual names of every male from twenty years ...