Reference for I Samuel 17:33

וַיֹּ֨אמֶר שָׁא֜וּל אֶל־דָּוִ֗ד לֹ֤א תוּכַל֙ לָלֶ֙כֶת֙ אֶל־הַפְּלִשְׁתִּ֣י הַזֶּ֔ה לְהִלָּחֵ֖ם עִמּ֑וֹ כִּֽי־נַ֣עַר אַ֔תָּה וְה֛וּא אִ֥ישׁ מִלְחָמָ֖ה מִנְּעֻרָֽיו׃ (ס)

And Saul said to David: ‘Thou art not able to go against this Philistine to fight with him; for thou art but a youth, and he a man of war from his youth.’