Kiddushin 4:1-2

Kiddushin 4:1

The following ten lineages returned from Babylonia with Ezra: kohanim, Leviim, Yisroelim, chalalim (i.e., offspring of kohanim unfit to serve), converts, freed servants, mamzers, Gibeonites, shtukei and asufei. Kohanim, Leviim and Yisroelim may all marry one another. Leviim, Yisroelim, chalalim, converts and freed servants may all marry one another. Converts, freed servants, mamzers, Gibeonites, shtukei and asufei may all marry one another.

Kiddushin 4:2

Shtukei are those who know their mothers but not their fathers. Asufei are foundlings from the marketplace who know neither their fathers nor their mothers. Abba Shaul called shtukei “bedukei” (from the word meaning to examine because the mother is examined to see if we can identify the father).