In a moment of profound national crisis and deep anxiety, David stands before King Saul and volunteers to battle Goliath. His appeal to the king is a masterful blend of passionate faith, diplomatic tact, and psychological insight. Seeking to calm the camp, David urges that no one should lose heart or succumb to fear [מצודת דוד]. He frames his encouragement by stating that no man should let his heart fail. This choice of words serves as a polite and dignified way of addressing King Saul directly, gently suggesting that the king himself should not let his own courage falter [ביאור שטיינזלץ]. The encouragement works on two complementary levels: a person must not allow his spirit to collapse internally, and he must not be terrified externally because of Goliath [רד״ק].
Beyond simple encouragement, focusing on the concept of a true human being carries profound spiritual weight. Goliath may be physically and materially massive, but he completely lacks the inner spiritual essence that defines a true person. An individual possessing genuine spiritual stature is inherently stronger than any purely physical force [מלבי״ם]. Furthermore, because Goliath cursed the armies of God, he forfeited his heavenly protection. He is no longer considered a human being at all, but is instead reduced to the level of a wild beast of the forest. Since it is the natural order for humans to cast fear upon wild animals, there is absolutely no reason for a true man to fear him [אלשיך].
When David declares his complete readiness to undertake the mission [ביאור שטיינזלץ], his willingness stems from a deep confidence in his own mental and spiritual resilience [מלבי״ם]. He emphasizes that he will fight specifically against this Philistine, implying that he is facing nothing more than flesh and blood. The enemy has been stripped of any heavenly guardian or spiritual power that might have protected him from above [אלשיך].
Alongside his unwavering faith, David's brief offer contains a brilliant diplomatic strategy designed to protect the king. By presenting himself merely as a servant, David creates a situation where the Israelites cannot truly lose. If he is defeated in battle, the morale of Israel's mighty warriors will remain intact, as onlookers will simply dismiss the failure as that of an inexperienced youth. Conversely, if he emerges victorious, all the glory and greatness will be credited to Saul. The surrounding nations will marvel that even a lowly servant of the king of Israel was able to bring down the great Philistine champion [חומת אנך].