'Purification' in the Bible

And when the days of their purification according to the law of Moses were fulfilled, they brought him up to Jerusalem, to present him to the Lord

Then Paul took the men, and the next day purifying himself with them went into the temple, declaring the fulfilment of the days of purification, until the offering was offered for every one of them.

who being the effulgence of his glory, and the very image of his substance, and upholding all things by the word of his power, when he had made purification of sins, sat down on the right hand of the Majesty on high;