What is the meaning of "ha'Ro'eh Atah"?
Rashi: If you see (think) that this is a good counsel, return to the city...
Radak citing Targum Yonasan: You are a Navi; Ru'ach ha'Kodesh came on you today, and answered you through the Urim v'Tumim.
Malbim #1: Make it seem that you yourself decided so, not that I instructed you, lest Avshalom suspect you. Through this, you will be able to spy for me what is happening in the city, and inform me.
Malbim #2: Do you see [via the Urim v'Tumim, letters that spell "return to the city"? This is a command to you!]
Why did he mention their sons?
Rashi: Through them you can inform me what you hear from Beis ha'Melech; based on what you tell me, I will flee.