New Revised Standard Version
Joab sent messengers to David, and said, “I have fought against Rabbah; moreover, I have taken the water city.

Contemporary English Version
and sent a messenger to tell David: I have attacked Rabbah and captured the fortress guarding the city water supply.

New American Bible
He sent messengers to David to say: “I have fought against Rabbah and have taken the water-city.

Douay-Rheims Bible
And Joab sent messengers to David, saying: I have fought against Rabbath, and the city of waters is about to be taken.

And Joab sent messengers to David, saying: I have fought against Rabbath, and the city of waters is about to be taken.

Rabbah

2 Samuel 11:1 And it came to pass at the return of the year, at the time when kings go forth to war, that David sent Joab and his servants with him, and all Israel, and they spoiled the children of Ammon, and besieged Rabba: but David remained in Jerusalem.

Deuteronomy 3:11 For only Og king of Basan remained of the race of the giants. His bed of iron is shewn, which is in Rabbath of the children of Ammon, being nine cubits long, and four broad after the measure of the cubit of a man's hand.

Ezekiel 21:20 Thou shalt make a way that the sword may come to Rabbath of the children of Ammon, and to Juda unto Jerusalem the strong city.