Say
As with many common verbs, the meaning of “to say” in the Bible is highly dependent on context. Who is speaking? Who is hearing? What is it about? Is it a command, a message, an apology, instruction? All these things enter into the meaning of “say.” In general, though, “saying” has to do with sharing truth at various levels -- from the most exalted power people can have to perceive the Lord's desires directly to the most basic of orders issued to people at their lowest.
Despise
We tend to think of "despising" something or someone as just a strong way of expressing dislike, but there is a further shade of meaning there. As the Free Online Dictionary puts it, it also means "to regard (something or someone) as unworthy of interest or concern." This meaning comes into play as "despise" is used in the Bible; it indicates that a person in a particular spiritual state cannot understand or value things belonging to a higher spiritual state, and thus regards them as nothing.