Kings I 26:25

25 And Saul said to David, Blessed thou, son; and thou shalt surely do valiantly, and surely prevail. And David went on his way, and Saul returned to his place.

Kings I 26:25 In-Context

23 And the Lord shall recompense each according to his righteousness and his truth, since the Lord delivered thee this day into my hands, and I would not lift my hand against the Lord's anointed.
24 And, behold, as thy life has been precious this very day in my eyes, so let my life be precious before the Lord, and may he protect me, and deliver me out of all affliction.
25 And Saul said to David, Blessed thou, son; and thou shalt surely do valiantly, and surely prevail. And David went on his way, and Saul returned to his place.

The Brenton translation of the Septuagint is in the public domain.