| Quote #1
His resons [the Merchant] spak ful solempnely,
Usually when someone gives "resons," it's in the context of a philosophical debate. But the Merchant's mind is on one thing and one thing only: money. We get the impression that his conversation is a bit monotonous!
| Quote #2
But al be that he was a philosophre,
Two things could be happening here: 1) This could be an ironic joke playing upon the fact that then, as now, we don't really expect someone who studies obscure topics for a living to have a whole bunch of money. 2) "Philosophre" actually means alchemist, someone who transforms base metals into gold.
| Quote #3
So greet a purchasour was nowher noon:
The Sergeant of the Law's financial success has allowed him to avoid something that, for medieval people, was a moral failing: debt. All the Sergeant of the Law's land is "fee simple," or purchased free and clear with ready money.