C. F. Keil and Franz Delitzsch on 1 Samuel 17:28

1Sa 17:28

David’s eldest brother was greatly enraged at his talking thus with the men, and reproved David: “Why hast thou come down (from Bethlehem, which stood upon high ground, to the scene of the war), and with whom hast thou left those few sheep in the desert?” “Those few sheep,” the loss of only one of which would be a very great loss to our family. “I know thy presumption, and the wickedness of thy heart; for thou hast come down to look at the war;” i.e., thou art not contented with thy lowly calling, but aspirest to lofty things; it gives thee pleasure to look upon bloodshed. Eliab sought for the splinter in his brother’s eye, and was not aware of the beam in his own. The very things with which he charged his brother - presumption and wickedness of heart - were most apparent in his scornful reproof.