Gather all Israel to Mizpeh - This appears to have been an armed assembly, though probably collected principally for religious and political purposes; but Samuel knew that an unarmed multitude could not safely be convened in the vicinity of the Philistines.

And Samuel said, Gather all Israel to (c) Mizpeh, and I will pray for you unto the LORD.
(c) For Shiloh was now desolate, because the Philistines had taken the ark from it.

And Samuel said, gather all Israel to Mizpeh,.... Not Mizpeh in Gilead, on the other side Jordan, but a city which lay on the borders of Judah and Benjamin, where the tribes met on the account of the Levite's concubine, Judges 20:1. This order Samuel gave by messengers sent to the several tribes, or the heads of them, to meet him at this place:
and I will pray for you unto the Lord; no doubt he prayed for them privately, that the reformation begun might be carried on, and appear to be sincere, and hearty, and general, and universal; but he was desirous that they might appear in a body, and join with him in public prayer for their spiritual and temporal welfare; that they might have true repentance for their sins, reform from them, and have remission of them, and be delivered out of the hands of their enemies.

Israel drew water and poured it out before the Lord; signifying their humiliation and sorrow for sin. They pour out their hearts in repentance before the Lord. They were free and full in their confession, and fixed in their resolution to cast away from them all their wrong doings. They made a public confession, We have sinned against the Lord; thus giving glory to God, and taking shame to themselves. And if we thus confess our sins, we shall find our God faithful and just to forgive us our sins.

Victory obtained over the Philistines through Samuel's prayer. - 1-Samuel 7:5, 1-Samuel 7:6. When Israel had turned to the Lord with all its heart, and had put away all its idols, Samuel gathered together all the people at Mizpeh, to prepare them for fighting against the Philistines by a solemn day for penitence and prayer. For it is very evident that the object of calling all the people to Mizpeh was that the religious act performed there might serve as a consecration for battle, not only from the circumstance that, according to 1-Samuel 7:7, when the Philistines heard of the meeting, they drew near to make war upon Israel, but also from the contents of 1-Samuel 7:5 : "Samuel said (sc., to the heads or representatives of the nation), Gather all Israel to Mizpeh, and I will pray for you unto the Lord." His intention could not possibly have been any other than to put the people into the right relation to their God, and thus to prepare the way for their deliverance out of the bondage of the Philistines. Samuel appointed Mizpeh, i.e., Nebi Samwil, on the western boundary of the tribe of Benjamin (see at Joshua 18:26), as the place of meeting, partly no doubt on historical grounds, viz., because it was there that the tribes had formerly held their consultations respecting the wickedness of the inhabitants of Gibeah, and had resolved to make war upon Benjamin (Judges 20:1.), but still more no doubt, because Mizpeh, on the western border of the mountains, was the most suitable place for commencing the conflict with the Philistines.