Sanhedrin 10: Split Testimony, Lashes, Intercalation

Today's daf covers three discussions.  The first is a continuation of yesterday's conversation regarding split testimony.  The rabbis offer a number of examples where testimony might be split.  These include a prohibition against a person killing his own wife after knowing that she has had an affair (thought it is permitted to join with another witness to kill the man involved).  Is this man related to his wife and thus not allowed to be a legal witness?  Another rabbis suggests that one is not punished by paying money if he has intercourse with an engaged girl; he is put to death.  If her name is mentioned, then he also pays money for he owes damages to her father.  Other examples demonstrate where a line must be drawn between oneself and one's relatives - or possessions - regarding testimony as a witness.

The rabbis consider cases where lashes are administered.  The Gemara notes that three judges are required for such a ruling, as described in our mishna.  The rabbis look to proof texts to determine why three and not two or four or seven judges might be required.  

Turning to those who give false testimony, the rabbis also search for proof texts.  False witnesses would be punished with lashes. As part of their discussion, the rabbis consider how many lashes should be administered in different circumstances.  Often we hear about "20 lashes", yet lashes should be in groups of three, it is argued, where two are on the back and one is on the front.  Thus after a doctor determines that a person will not die from 20 lashes, 18 lashes are administered to keep the lashes in groups of 3.  If one more lash were given and the person were to die, any further lashes would be applied to a dead body.  This would go against Torah law.

Finally, the Gemara turns to the intercalation of the month.  The rabbis discuss the timing of the decision-making around determining the new month.  Why isn't the month determined earlier in the year?  If we assume that the days of the month will change, what should we do?  Do we wait for the last minute to change the days of the month?  Or not?  The rabbis recognize that the intercalation of the month has implications on each community.