When the Lord has washed away the filth of the daughters of Zion, and has washed away the blood in a spirit of judgment and a spirit of purging. Isa. 4:4.

If you wash yourself with soda and use soap repeatedly on yourself, still your iniquity will retain its stains. Jer. 2:22; Job 9:30, 31.

Wash me from my iniquity and I shall be whiter than snow. Ps. 51:2, 7.

Wash your heart free from wickedness, Jerusalem, so that you may be saved. Jer. 4:14.

Wash yourselves, cleanse yourselves, put away the wickedness of your deeds from before my eyes, cease to do evil. Isa. 1:16.

[2] The washing of a person's spirit is meant by the washing of his body; and the internals of the church were represented by such external rituals as were practised by the Israelite church. This is obvious from the Lord's words in this passage:

The Pharisees and Scribes, seeing that His disciples ate bread with unwashed hands, found fault. For the Pharisees and all Jews do not eat unless they have washed their hands up to the fist; there are many other things they have accepted as a practice to be kept up, such as the washing of cups and pots, and of bronze vessels, and beds. The Lord said to them and to the crowd, Listen to me all of you and understand. There is nothing outside a person which can make him unclean if it enters into him; but it is what comes out that makes him unclean. Mark 7:1-4, 14, 15; Matt. 15:2, 11, 17-20.

Also elsewhere:

Woe to you, Scribes and Pharisees, because you clean the outside of the cup and dish, but the inside is full of robbery and violence. You blind Pharisee, clean first the inside of the cup and dish, so that the outside too may be clean. Matt. 23:25, 26.

It is plain from these passages that the washing called baptism stands for spiritual washing, which is being purified from evils and falsities.