Adam Clarke on 1 Samuel 17:43

Am I a dog, that thou comest to me with staves? - It is very likely that Goliath did not perceive the sling, which David might have kept coiled up within his hand.

Cursed David by his gods - Prayed his gods to curse him. This long parley between David and Goliath is quite in the style of those times. A Hindoo sometimes in a fit of anger says to his enemy, The goddess Kalee shall devour thee! May Doorga destroy thee! Homer's heroes have generally an altercation before they engage; and sometimes enter into geographical and genealogical discussions, and vaunt and scold most contemptibly.