16 Now the Pharisee made great preparations for our Lord in His banquet; and the sinful woman did but little things for Him there. Yet he by his great dainties displayed the smallness of his love to our Lord; but she by her tears displayed the greatness of her love to our Lord. Thus he that had invited Him to the great banquet was rebuked because of the smallness of his love; but she by her few tears atoned for the many follies of her offenses. Simon the Pharisee received our Lord as a prophet; because of the signs, and not because of faith.
For he was a son of Israel, who when signs drew near, himself also drew near to the Lord of the signs; and when the signs ceased, he also stood naked without faith. This man also when he saw our Lord with signs, esteemed Him as a prophet; but when our Lord ceased from signs, the doubting mind of the sons of his people entered him. This man if He had been a prophet, He would have known that this woman is a sinner. But our Lord for Whom in every place all things are easy, here also did not cease from His signs.
For He saw that because He had ceased a little from signs, the blind mind of the Pharisee had turned away from Him. For he had said in error, This man, had He been a prophet, He would have known. In this reflection therefore the Pharisee doubted concerning our Lord, whether He were a prophet or no; but by this very reflection he learned that He is Lord of the prophets; so that from the source from which error entered him, from that source our Lord might bring help to Him.
Source: On Our Lord (New Advent)