The Routing Of The Philistines (1 Samuel 17:51-54).
Having brought the Philistine down David ran over to him and cut off his head with his own sword, and on seeing their champion humbled the Philistines had no further stomach for a fight. Terror appears to have taken hold of them, for they could no doubt see the Israelite army suddenly emboldened and ready to attack. And when they did so, what greater evidence of what the God of Israel could do to them did they need than this? They turned and fled leaving their baggage behind (wagons would only have delayed them). All defiance was over.
The exuberant Israelites meanwhile gave out a loud war-cry and chased after them, following them all the way to their own cities, slaughtering those who were too slow, after which they plundered the camp which the Philistines had left behind. And David, having cut off the head of his opponent took it up to Jerusalem of Judah, where the men of Judah regularly celebrated their triumphs (Judges 1:7), while his armour he put in his own tent.
Analysis.
a Then David ran, and stood over the Philistine, and took his sword, and drew it out of its sheath, and slew him, and cut off his head with it (1 Samuel 17:51 a).
b And when the Philistines saw that their champion was dead, they fled. And the men of Israel and of Judah arose, and shouted, and pursued the Philistines, until you come to Gai, and to the gates of Ekron (1 Samuel 17:51-52 a).
c And the wounded of the Philistines fell down by the way to Shaaraim, even to Gath, and to Ekron (1 Samuel 17:52 b).
b And the children of Israel returned from chasing after the Philistines, and they plundered their camp (1 Samuel 17:53).
a And David took the head of the Philistine, and brought it to Jerusalem, but he put his armour in his tent (1 Samuel 17:54).
Note that in ‘a' David cuts off Goliath's head, and in the parallel he brings it to Jerusalem. In ‘b' the victorious Israelites chase the fleeing Philistines, and in the parallel they return from doing so and plunder their camp. Centrally in ‘c' the Philistines, far from defying Israel and YHWH, are humiliated all the way home.
‘ Then David ran, and stood over the Philistine, and took his sword, and drew it out of its sheath, and slew him, and cut off his head with it. And when the Philistines saw that their champion was dead, they fled.'
So he ran over to where the Philistine had fallen, stood over him, took out the Philistine's own sword from its sheath, and slew him and cut off his head. The Philistines were meanwhile struck with awe and terror. They could hardly conceive how it had happened. And recognising that the gods must be against them, and that the Israelite army, whom they could see mobilising, would soon arrive in strength, they turned and fled. Of what use fighting when even the gods seemed against them? They would simply be cut to pieces.
‘ And the men of Israel and of Judah arose, and shouted, and pursued the Philistines, until you come to Gai, and to the gates of Ekron. And the wounded of the Philistines fell down by the way to Shaaraim, even to Gath, and to Ekron.'
Having watched in silence the unexpected turn of events the men of Israel in their turn became exultant. Most of them probably could not believe their eyes. The huge warrior who had defied them day after day now lay dead, slain by an Israelite shepherd boy. It was clear that YHWH was fighting with them and was on their side. And they arose and yelled their war cries, and then pursued the Philistines all the way to Gai, to the very gates of Ekron. And as they pursued they put the stragglers to the sword, and wounded men fell down by the road to Shaaraim, all the way to Gath and Ekron. And what a story they would have to tell.
Gai means ‘valley'. It was possibly the name given to a town situated in a well known valley, or to a prominent valley which had become known as ‘The Valley'. ‘The road to Shaaraim' would be a recognised highway. The picture of wounded men falling by the wayside all along the route is in contrast with their previous defiance. They are defiant no longer. (The whole makes an interesting comparison with how the statue of Dagon also lost its head and fell before the Ark in 1 Samuel 5:4).
‘ And the children of Israel returned from chasing after the Philistines, and they plundered their camp.'
Once the chase was over the children of Israel then returned from chasing the Philistines, and plundered their camp and all their wagons, filled with praise to YHWH.
‘ And David took the head of the Philistine, and brought it to Jerusalem, and he put his armour in his tent.'
And David meanwhile took the head of the Philistine back to his shepherd's tent which was by Jerusalem where he had been pasturing his sheep (Bethlehem was only five miles from Jerusalem), and he put the Philistine's armour in his tent. He would certainly get a nice feeling every time he looked at it, and it would remind him of YHWH's goodness in giving him victory.
“Brought it to Jerusalem.” If David's shepherd encampment was near Jerusalem it make perfect sense for him to bring Goliath's head back to his tent along with his armour. However, there are grounds elsewhere for seeing Jerusalem of Judah as the place to which men of Judah regularly brought the trophies of victory. See, for example, Judges 1:7, where after they had defeated Adoni-bezek the men of Judah ‘brought him to Jerusalem' (the part of Jerusalem occupied by Judah). Thus it may be that that was why David of Judah saw this as the place to which to bring his trophy.
There appears to have been a threefold Jerusalem, for it was on the border of Judah and Benjamin and covered a wise area. There was the unconquered Jebusite citadel on the highest hill of Jerusalem, which would later fall to David, and then there was a Benjaminite Jerusalem (Judges 1:21) and a Jerusalem belonging to Judah (Judges 1:7-8), both of which were necessarily on other hilltops outside the citadel.
Others see ‘and brought it to Jerusalem' as referring to what David did later in the future after he had captured the Jerusalem fortress. But Jerusalem of Judah had been held by them for a long time and was clearly seen by them as important (Judges 1:8) so that there is no reason why David should not be seen as visiting Jerusalem in Saul's day, especially if the people of Judah saw it as their main city.