2,238. Confirming a Kohein From a Document

Hilchos Issurei Biah 20:8

If an established kohein arrives with sons and says that he married a woman who died and these are his children with her, he must bring witnesses that the woman was halachically fit and that these are her children. All these laws also apply to an Yisroel and a Levi of confirmed pedigree. One can then testify about such a son so that he will be fit to serve on the Sanhedrin.

Hilchos Issurei Biah 20:9

We don’t confirm a kohein’s lineage based on a document. If a document says, “Person X the kohein borrowed amount Y from person Z” and witnesses sign, we don’t presume that this kohein is of fit lineage because they might have only signed to confirm the loan. This is only the case when it comes to confirming his lineage as a kohein. When it comes to the presumption that he’s a kohein like the other kohanim nowadays, with permission to eat only rabbinic-level trumah and challah and other portions given only in Israel, that may be done based on a document, the testimony of one witness, or the fact that this person recites birkas kohanim or receives the first aliyah.