This verse is part of a deceptive strategy by Hushai, David's friend and advisor, to undermine Absalom's rebellion. Let's break it down to understand its meaning:

Context: Absalom has usurped the throne from his father, David. Hushai, loyal to David, pretends to switch allegiance to Absalom in order to provide intelligence and disrupt Absalom's plans. Absalom is suspicious of Hushai's sudden change of heart.

Hushai's statement: "Hushai said to Absalom, 'No; but whomever Yahweh, and this people, and all the men of Israel have chosen, his will I be, and with him I will stay.'"

Explanation:
"No;": This seems to initially contradict Absalom's suspicion. However, it's likely a rhetorical technique to grab Absalom's attention.
"whomever Yahweh, and this people, and all the men of Israel have chosen, his will I be, and with him I will stay.": This is the key part. Hushai is carefully wording his loyalty. He's implying that because Absalom is now in power, he is the one "chosen" by God, the people, and Israel.

It's a conditional allegiance, but presented in a way that sounds devout and supportive of the current power structure.
Hushai cleverly avoids directly declaring allegiance to Absalom by name.
He is not making any outright lies, but using ambiguity to his advantage.

Meaning and Deception:

Hushai's statement is a carefully crafted piece of deception. He's trying to convince Absalom that his loyalty lies with whoever is currently in power.
He implies divine and popular support for Absalom, thus playing to Absalom's ego and insecurities.
Hushai's actual loyalty is to David, but this statement is designed to make Absalom trust him and accept him as an advisor.

In essence, Hushai is flattering Absalom and creating a false sense of security in order to gain access to Absalom's inner circle and ultimately help David regain his throne. He’s playing the political game with cunning and deceit.