| Quote #1
But certeinly, er he came fully there,
This passage suggests that the wife the knight sees sitting on the green is "foul" in part because she's old. It does this with the way it calls her an "this olde wyf" immediately after calling her "foul," with the expectations that the audience will already know she's foul.
| Quote #2
Agayn the knyght this olde wyf gan ryse,
This passage equates wisdom with age. The old wife the knight sees tells him that "thise olde folk kan muchel thyng." The reason for this knowledge might be the many years of lived experience, experience being a form of knowledge the Wife of Bath has privileged in her Prologue.
| Quote #3
'Nay, thanne,' quod she, 'I shrewe us bothe two!
It's interesting that the loathly lady recites all the reasons why the knight might not want to marry her with her "though that I be foul, and oold, and poore." It's almost as if she's trying to rub the knight's face in it.