99:2 An egg that was laid on yom tov may not be handled but one may cover it with a vessel to keep it from breaking. If it was laid on the first day of yom tov, the egg may be eaten on the second day unless the second day also happens to be Shabbos. Similarly, if the first day was Shabbos and the egg was laid on Shabbos, it may not be eaten on the second day of yom tov. When Shabbos is next to yom tov, whether before or after it, if the egg was laid on one day, it is forbidden on the other day. Also on Rosh Hashana, an egg laid on the first day is forbidden on the second because the two days of Rosh Hashana are considered like one long day with a continuous level of sanctity.
Things that one may not do from the first day to the second day of other holidays are discussed in chapter 101. Such things are no different between Rosh Hashana and the other holidays because these things are prohibited on Rosh Hashana as well; there are no lenient ramifications from its status as one long day. Therefore, if Rosh Hashana fell on Thursday and Friday, even if the egg was laid on Thursday, it may not be eaten on Shabbos. If a chicken was slaughtered and one found eggs in it, even if they are completed, they are permitted even on the same day.
99:3 Handling wood was only permitted for the purpose of kindling a fire; when not required for kindling, it may not be handled. Therefore, one should not use it to support a pot or to prop open a door.