1,242. Accepting the Witnesses
Hilchos Kiddush HaChodesh 2:3
If the court was not familiar with the witnesses who saw the moon, the residents of the city where the moon was seen would send other witnesses with them to serve as character witnesses and to inform the court that they are acceptable to serve as witnesses. After this, the court would accept their testimonies.
Hilchos Kiddush HaChodesh 2:4
As noted, the court made calculations similar to those of astronomers so they would know if the moon would be sighted to the north or the south of the sun, how wide or narrow it would be and in which direction its corners would point. When the witnesses arrived, the court would ask them about all these details. If their replies were appropriate, their testimonies would be accepted; if their replies were not appropriate, their testimonies would not be accepted.