13 And David became famous after he returned from striking down eighteen thousand Edomitesa in the Valley of Salt.

Read 2 Samuel 8:13 Using Other Translations

And David gat him a name when he returned from smiting of the Syrians in the valley of salt, being eighteen thousand men.
And David made a name for himself when he returned from striking down 18,000 Edomites in the Valley of Salt.
So David became even more famous when he returned from destroying 18,000 Edomites in the Valley of Salt.