1,241. Who May Testify Regarding the Moon

Hilchos Kiddush HaChodesh 2:1

The only testimony that is accepted regarding the moon is that of two adult males who are qualified to testify in all matters. The testimony of women and servants is not accepted in this matter. If a father and son both see the moon, they should both go the court to testify. This is not because testimony regarding the moon is accepted from relatives but out of concern that one of their testimonies might be disqualified. In such a case, the other’s testimony can be joined with that of another witness. If a person is disqualified as a witness by rabbinic law, he may not serve as a witness regarding the moon even though he is acceptable as a witness under Torah law.

Hilchos Kiddush HaChodesh 2:2

The Torah does not require precision regarding the testimony about the moon. If the new month was sanctified based on the testimony of witnesses and it was then discovered that those witnesses had lied, the month remains sanctified. Because of this, the earlier generations accepted testimony about the moon from any Jew, since any Jew is presumed to be a valid witness unless one knows otherwise for a fact. When the Boethusians started rebelling, they would hire people to testify that they had seen the moon when they really hadn’t. Accordingly, the court started only accepting testimony in this matter from witnesses whom they knew to be acceptable. Furthermore, they started to examine the witnesses and question their testimonies.