1st Samuel 17:33

30 And he turned from him toward another, and spake after the same manner: and the people answered him again after the former manner.

31 And when the words were heard which David spake, they rehearsed them before Saul: and he sent for him.

32 And David said to Saul, Let no man's heart fail because of him; thy servant will go and fight with this Philistine.

33 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.

34 And David said unto Saul, Thy servant kept his father's sheep, and there came a lion, and a bear, and took a lamb out of the flock:

35 And I went out after him, and smote him, and delivered it out of his mouth: and when he arose against me, I caught him by his beard, and smote him, and slew him.

36 Thy servant slew both the lion and the bear: and this uncircumcised Philistine shall be as one of them, seeing he hath defied the armies of the living God.