571. What May Not Be Done on Shabbos

Milah 2:7

Medicinal herbs for a bris may not be ground on Shabbos, nor may water be heated, nor a compress prepared, nor may wine and oil be mixed. If cumin wasn’t ground before Shabbos, it may be chewed on Shabbos and applied. If wine and oil were not mixed together before Shabbos, each one may be applied separately. The general principle is that whatever could have been done before Shabbos does not override Shabbos. If one forgot and did not prepare items needed for a bris, the bris should be performed on the ninth day.

Milah 2:8

If a baby was circumcised on Shabbos and then the hot water got spilled or the medicinal herbs got scattered, one may do whatever is necessary for the baby on Shabbos because of the danger to the patient. In a place where the accepted practice is to wash the baby, he may be washed on Shabbos when that is the day of his bris - both before the bris and after - and when it is the third day from the bris. The baby’s whole body may be washed, not just the place of the bris. He may be washed with water that was heated before Shabbos or even on Shabbos because the potential danger.