"And the Lord said unto him, Now do ye Pharisees make clean the outside of the cup and the platter; but your inward part is full of ravening and wickedness. Ye fools, did not He, that made that which is without, make that which is within also?" (Luke 11:39-40)
Robertson's Word Pictures made this statement - "Both inside and outside should be clean, but the inside first."
Adam Clarke offered this remark on this particular verse of Scripture - "A man may appear clean without who is unclean within; but outward purity will not avail in the sight of God , where inward holiness is wanting."
The Pharisees were notorious for keeping external regulations of the Law in order to look good unto men. Thy were concerned with outward purity and observances. They were very strict in the washings of their bodies, cups, and platters. Consequently, outwardly, they appeared quite righteous.
They stressed the observance of rites and rituals that came under the eye of man, but ignored the inner man which came under the eye of God. Inwardly, their souls were full of all manner of sin. Inwardly, they were crooked and wicked. Inwardly, they were dirty - filled with self-righteousness, pride, and hypocrisy. On the inside, they loved sin. They took pains to appear well but had no regard for inward purity.
Jesus' command to them was - "Make sure you cleanse the heart first."
Nowadays, we have many "Pharisees" in the church who avoid all of the scandalous sins that would dare to spoil their reputation among men. However, they allow in themselves heart-wickedness - like hatred, bitterness, unforgiveness, pride, lust, jealousy, and strife - which renders them odious to a pure and holy God.
God sees the"outside" and the "inside" of the "cup" and "platter." In other words, He sees the vessel through and through.
Before you ever step out to be used of God, be sure that you are clean on the inside - the part that God sees.
"Thou blind Pharisee, cleanse first that which is within the cup and platter, that the outside of them may be clean also" (Matthew 23:26).
Don't ever ask God to fill your cup when it hasn't been made clean on the inside!
Remember - "...outward purity will not avail in the sight of God, where inward holiness is wanting."