SEV Biblia, Chapter 17:33
Y dijo Saúl a David: No podrás tú ir contra aquel filisteo, para pelear con él; porque tú eres niño, y él es un hombre de guerra desde su juventud.
Clarke's Bible Commentary - 1 Samuel 17:33
Verse 33. Thou art but a youth] Supposed to be about twenty- two or twenty-three years of age.
John Gill's Bible Commentary
Ver. 33. And Saul said to David, thou art not able to go against this Philistine to fight with him , etc.] Had neither strength of body, nor skill in military affairs, to encounter with a man of his stature, and warlike genius and practice: for thou [art but] a youth ; some say about fourteen or sixteen years of age, but very probably about twenty, and not more, and so not only weak, but inexpert in the art of fighting: and he a man of war from his youth ; a gigantic man, trained up in, inured to, and expert in the affairs of war; so that David could not, on any account, be a competitor with him, and a match for him.
Matthew Henry Commentary
Verses 31-39 - A shepherd lad, come the same morning from keeping sheep, had mor courage than all the mighty men of Israel. Thus God often sends goo words to his Israel, and does great things for them, by the weak an foolish things of the world. As he had answered his brother's passio with meekness, so David answered Saul's fear with faith. When Davi kept sheep, he proved himself very careful and tender of his flock This reminds us of Christ, the good Shepherd, who not only ventured but laid down his life for the sheep. Our experience ought to encourag us to trust in God, and be bold in the way of duty. He that ha delivered, does and will continue to do so. David gained leave to figh the Philistine. Not being used to such armour as Saul put upon him, he was not satisfied to go in that manner; this was from the Lord, that is might more plainly appear he fought and conquered in faith, and tha the victory was from Him who works by the feeblest and most despise means and instruments. It is not to be inquired how excellent any thin is, but how proper. Let Saul's coat be ever so rich, and his armou ever so strong, what is David the better if they fit him not? But faith, prayer, truth, and righteousness; the whole armour of God, an the mind that was in Christ; are equally needful for all the servant of the Lord, whatever may be their work.
Original Hebrew
ויאמר 559 שׁאול 7586 אל 413 דוד 1732 לא 3808 תוכל 3201 ללכת 1980 אל 413 הפלשׁתי 6430 הזה 2088 להלחם 3898 עמו 5973 כי 3588 נער 5288 אתה 859 והוא 1931 אישׁ 376 מלחמה 4421 מנעריו׃ 5271