2 What is that “woman who was in an infirmity eighteen years”? In six days God finished His works. Three times six are eighteen. What the “three years” then in “the tree” signified, that do the “eighteen years” in this woman. She was bent down, she could not look up; because in vain did she hear, “Up with your hearts.” But the Lord made her straight. There is hope then, for the children, that is, even until the day of judgment come. Man ascribes much to himself. Yet what is man?
A righteous man is something great. But yet a righteous man is righteous only by the grace of God. “For what is man, save that you are mindful of him?” Would you see what man is? “All men are liars.” We have chanted, “Arise, Lord; let not man prevail.” What is, “let not man prevail”? Were not the Apostles men? Were not Martyrs men? The Lord Jesus Himself, without ceasing to be God, vouchsafed to be Man. What then is, “Arise, Lord; let not man prevail”? If “all men are liars; arise,” Truth, “let not” falsehood “prevail.” If man then would be anything good, it must not be of anything of his own. For if he should wish to be anything of his own he will be “a liar.” If he would wish to be true, he must be so of that which is from God, not of anything of his own.
Source: Sermons on Selected Lessons of the New Testament (New Advent)