2 Samuel 2:4

They anointed David. Samuel's anointing ( 1 Samuel 16:13 ) had been private, and, if we may judge by the manner in which Eliab treated David ( 1 Samuel 17:28 ), even his own family had not attached much importance to it. It was nevertheless the indication of Jehovah's purpose, and now the anointing of David by the elders of Judah was the first step towards its accomplishment. And this was an independent act, though the knowledge of Samuel's anointing had prepared the way for it; and David thus acquired a legal right and authority by the nation's will, which Samuel could not have given him. So Saul's anointing by Samuel, and his election to be king at Gilgal, were independent acts; and while the former gave the king his sacredness, the latter conferred upon him jurisdiction and power. King over the house of Judah. How came the Philistines to allow this? When subsequently he was again anointed, and became King of all Israel, the Philistines gathered their hosts at once; not because he captured Jerusalem, which was then a mere hill fort belonging to the Jebusites, but evidently because they thought him dangerous. But why did they not crush him now? One reason, probably, was that Judaea was a difficult country for military operations. The tribe, too, had stood aloof from Saul, and its strength was unbroken. But the chief reason apparently was that David maintained friendly relations with Achish, and paid him tribute. This explains the curious fact that Ziklag continued to be the private property of the house of David ( 1 Samuel 27:6 ). The doings of a vassal of the King of Gath were regarded as of little importance. Had he not even marched with them to Aphek, as one of the servants of Achish? But when he endeavoured to restore the kingdom of Saul, they first made a hasty rush upon him, and, when repelled, they gathered their forces for as formidable an invasion as that which had ended in their victory at Gilboa.