The second person verbs in the previous verse were plural, but in verses 23-24 they are singular, as if the Assyrian official is addressing Hezekiah directly.
Come now is literally “And now.” These transition words in the original text are sometimes ignored by modern versions, but many languages will require something at this point. The words signal the fact that the speaker is moving from a general discussion to a more specific proposal. New Jerusalem Bible attempts to show this by beginning the verse with “Very well, then.” Revised Standard Version may also be including the Hebrew particle of entreaty in its rendering Come now. Nouvelle Bible Segond begins with “Now … I pray”
Make a wager is literally “pledge yourself,” which is followed by the Hebrew particle of entreaty (see the comments on verse 19). The Hebrew verb used here is related to the noun translated elsewhere as “surety” (Gen 43.9; Pro 11.15). According to the proposition that follows later in this verse, the deal would be one in which each party would be required to do something, but if Hezekiah failed in his part of the bargain, the Assyrian king would not have to keep his part. Many modern versions retain the word wager, and Contemporary English Version even has “make a bet.” But this seems misleading. Revised English Bible is probably better with “make a deal.” La Bible du Semeur provides another possible model, saying “I issue you a challenge.”
With my master: The Assyrian official is not proposing that Hezekiah go to the king of Assyria and make a deal there. Rather, he is suggesting that a deal be made on the spot between the kings of Judah and Assyria with himself acting on behalf of the Assyrian king. Good News Translation and La Bible du Semeur seek to convey this idea by adding the words “in the name of.” Something similar may be required in other languages. For the whole clause still others may use a reciprocal verb meaning something like “let’s make a deal between you and my master.”
I will give you two thousand horses, if you are able on your part to set riders upon them: In some cases the order of the clauses here may need to be reversed, placing the if clause first, in order to make it sound more natural; for example, some may say something like the following: “If you [singular] can find two thousand men who can ride horses, then I will give you two thousand horses.”
Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on 1-2 Kings, Volume 2. (UBS Helps for Translators). New York: UBS, 2008. For this and other handbooks for translators see here .