Verse 7: And when the Philistines heard that the children of Israel were gathered together to Mizpeh, the lords of the Philistines went up against Israel. And when the children of Israel heard it, they were afraid of the Philistines.
[They went up into Israel] Hebrew: אֶל/towards; that is, against Israel. Thus אֶל is taken in 2 Samuel 5:19 (Mendoza). Unto the twentieth year after the return of the Ark, arms were silent on both sides; because both had enough to do to take care of their own, and to strengthen themselves after the infliction of both plagues; neither were they thinking it safe, or opportune, to disturb the other’s affairs (Sanchez). Why then do the Philistines now have recourse to arms? Responses: 1. Becauses the Philistines had prohibited the Israelites from forming congregations of the people (Lyra, Tostatus), so that thus they might separate them, and keep them apart, and remove the occasion for rebellion (Tostatus in Mendoza). 2. They suspected the rebellion of the Israelites (Cajetan in Mendoza), and that they were about to set something subversive in motion (Malvenda), and that something for their freedom was being prepared by them (Sanchez). Although the Hebrews wrought repentance, they were more grievously assailed by the Philistines. So those that wish to return to better fruit are more sharply tempted by the Devil, and endure greater persecutions from men (Mendoza).
The lords of the Philistines went up, to wit, with all army, verse 10, suspecting the effects of their general convention, and intending to nip them in the bud.
[When they had heard, they feared from before the Philistines] As if at the same time both the report was heard, and their presence was discerned: This sudden coming of their enemies was the cause of their terror. To which were added, 1. their awareness of their own sin. 2. The unequal condition of the two armies. For the Hebrews were unarmed, since they came for sacrifice and prayer: the Philistines were armed, since they came for battle (Mendoza). Samuel, while he desires to free the people, appears to have brought the gravest of dangers upon them (Martyr). Therefore, they could accuse him of imprudence or rashness. Wherefore, when we enter upon counsels of which God approves, if anything adverse should happen, let us not repent of the deed, nor turn from the right way, but acquiesce in the will of God (Calvin).
They were afraid; being a company of unarmed persons, and unfit for battle.
 Hebrew: וַיִּשְׁמְע֣וּ פְלִשְׁתִּ֗ים כִּֽי־הִתְקַבְּצ֤וּ בְנֵֽי־יִשְׂרָאֵל֙ הַמִּצְפָּ֔תָה וַיַּעֲל֥וּ סַרְנֵֽי־פְלִשְׁתִּ֖ים אֶל־יִשְׂרָאֵ֑ל וַֽיִּשְׁמְעוּ֙ בְּנֵ֣י יִשְׂרָאֵ֔ל וַיִּֽרְא֖וּ מִפְּנֵ֥י פְלִשְׁתִּֽים׃  Hebrew: וַיַּעֲל֥וּ סַרְנֵֽי־פְלִשְׁתִּ֖ים אֶל־יִשְׂרָאֵ֑ל.  2 Samuel 5:19: “And David enquired of the Lord, saying, Shall I go up to the Philistines (אֶל־פְּלִשְׁתִּים, against the Philistines)? wilt thou deliver them into mine hand? And the Lord said unto David, Go up: for I will doubtless deliver the Philistines into thine hand.”  Hebrew: וַֽיִּשְׁמְעוּ֙ בְּנֵ֣י יִשְׂרָאֵ֔ל וַיִּֽרְא֖וּ מִפְּנֵ֥י פְלִשְׁתִּֽים׃.