'Clean' in the Bible

And he said, In peace: I have come to make an offering to the Lord: make yourselves clean and come with me to make the offering. And he made Jesse and his sons clean, and sent for them to be present at the offering.

Nevertheless Saul spake not any thing that day: for he thought, Something hath befallen him, he is not clean; surely he is not clean.

David answered the priest, “Be assured that women have been kept from us in these three days since I set out, and the bodies of the young men were consecrated (ceremonially clean), although it was an ordinary (unconsecrated) journey; so how much more will their vessels be holy today?”