'Holy to the Lord' in the Bible

For there were many in the assembly who had not consecrated themselves [that is, become ceremonially clean and free from all sin]; so the Levites had to slaughter the Passover lambs for everyone who was not clean, in order to make them holy for the Lord.

To the Levites who taught all Israel and were holy to the Lord he said, “Put the holy ark in the house (temple) which Solomon the son of David king of Israel built; it shall not be a burden [carried] on your shoulders any longer. Now serve the Lord your God and His people Israel.