The Old Woman in the "Wife of Bath's Tale" says that a gentleman is one who "loves to work for virtuous ends, Public or private, and who most intends to do what deeds of gentleness he can, Take him to be the greatest gentleman. Christ will we take our gentleness from Him, Not from a wealth of ancestry long and dim, though they bequeath their whole establishment By which we claim to be of high descent."
She is rebuking the knight for finding fault with her for being old and ugly, for being poor, and for being ill-bred and not of a wealthy and respected family. She gives him a tongue-lashing and points out that Christ was the best and most perfect of all men on earth, and neither was he born into a wealthy family, nor did he wear beautiful clothes. He was, however, gentle and kind to everyone he met, as the Old Woman has been. She does not understand his greed and his anger toward her since she has done nothing to wrong him.
She then gives him the choice which is the climax of the story: keep her as she is--old, ugly, poor, but loyal and a good wife always to him OR young, beautiful, and unfaithful. The knight, knowing her to be right about all the points in her speech and the fault she finds with him, leaves the choice to her to make.
She chooses to be--young, beautiful and faithful. This wraps up the Wife's point, that women want equality in decision-making in the home. Since the knight left the choice with her, he gets it all.
My particular version of The Canterbury Tales does not have numbered lines, and even those versions that do have numbered lines differ from edition to edition, but I am going to assume you are referring to these lines from "The Wife of Bath's Tale" -
"Look for the man who's always virtuous in private and in public, does his best always to do what gentle acts he can, and count him for the greatest gentleman...for Christ wants us to claim nobility from Him...their goodness...their virtuous way of life which earned for them the name of gentlemen".
The old woman is saying that the chief qualification of a gentleman is virtue, his ability to act decorously at all times, being gentle and kind both in public and in private, in imitation of the goodness Christ exemplified.