We might easily pass over this story as being quaint or charming, but it is much more than that. God intends it as an object lesson to us on our responsibility to perform acts of kindness. It also teaches us a great deal about David's heart and why he was beloved of God.
Saul and three of his four sons had been killed in battle on Mount Gilboa. A fourth son survived only to be assassinated, ending an attempt to set up a rival kingdom. All that remained of the once high and proud house of Saul were some daughters and some sons by a concubine. Meanwhile, David prospered as he consolidated his kingdom by gaining victories everywhere he went.
Despite David's high station and prosperity, he did not forget his and Jonathan's oath or their love for each other when David was the lowly shepherd and Jonathan was heir to the throne. The story gives no indication that anyone prompted David's inquiry. The request came from his own heart, motivated by his faithfulness to his friend and his caring nature.
This seems more remarkable when we consider his undeserved persecutions at Saul's hand, as the aging king became increasingly crazed from jealousy of David's popularity. David could easily have been bitter from having been forced into living the life of a vagabond, dwelling in caves, and existing on the generosity of others while he was doing good for Israel. He could have held a grudge in order to feel justified in retaliating, or spat curses against any of Saul's heirs. Besides, it was the way of Eastern kings to kill off any potential claimants to the throne.
Instead, what came welling up in David's heart was a spontaneous and self-motivated desire to do good to any who remained of Saul's house. But David's language as he questioned Ziba goes still deeper in unfolding his motives. He speaks of showing the "kindness of God" to Saul's house, elevating his motive to an even higher plane as a precursor of Jesus' statement in Luke 6:35-36:
But love your enemies, do good, and lend, hoping for nothing in return; and your reward will be great, and you will be sons of the Highest. For He is kind to the unthankful and evil. Therefore be merciful, just as your Father also is merciful.
David's statement reveals that he was constrained to use God as the pattern for what he wanted to do for Saul's house. He recognized that he, a sinner like all of us, had received undeserved mercy and kindness from the hand of God. It is as if God is saying that, before we can pass on His kindness, we must first recognize that we have received it from Him. Jesus follows up His statement with another that touches on this area: "Therefore I say to you, her sins, which are many, are forgiven, for she loved much. But to whom little is forgiven, the same loves little" (Luke 7:47).
David's touching example of kindness reveals that he felt responsible to be merciful and kind because our great God had been exceedingly merciful and kind to him by forgiving much and giving much. He is a worthy example of one who loved much because he recognized that God loved him.
The best basis for kindly service to man is experiencing God's mercy. Indeed, we can say that long before a person can be truly merciful, God has been merciful to him. Religion is not pure and undefiled unless it manifests itself in this quality of kindly given service (James 1:27). Perhaps from this example, we can draw the conclusion that we have not shown our brother all the kindness we owe him unless we have shown him the "kindness of God."