Poole on 1 Samuel 4:10, 11: Israel Defeated! the Sons of Eli Slain! the Ark Lost!
Verse 10: And the Philistines fought, and (1 Sam. 4:2; Lev. 26:17; Deut. 28:25; Ps. 78:9, 62) Israel was smitten, and they fled every man into his tent: and there was a very great slaughter; for there fell of Israel thirty thousand footmen.
Into his tent, that is, to his habitation, called by the ancient name of his tent.
[Thirty thousand footmen] Question: But did no horsemen fall? Response: Perhaps there were none; 1. Because of the poverty of that time, and the preciousness of horses; 1 Kings 10:29. 2. Because of the divine law, Deuteronomy 17:16 (Mendoza). In which God prohibited to them, if not the use, certainly the abundance of horses (Lapide). Before the coming of the Ark, only four thousand were killed; after, thirty thousand. For it is hardly fitting, that the wicked should be helped by the presence of the Ark; but rather that they should be delivered to a greater destruction (Mendoza). That is, that they were more sharply punished because of the crime of violating the Ark and the Temple, by outraged Deity, and now in the presence of the Ark (Lapide).
Thirty thousand: Before they lost but four thousand, now in the presence of the ark thirty thousand, to teach them that the ark and ordinances of God were never designed for sanctuaries or refuges to impenitent sinners, but only for the comfort and relief of those that repent. Horsemen are not mentioned; either, first, Because they had few or none, God having forbidden the multiplication of their horses, Deuteronomy 17:16, and the Philistines, their lords and oppressors, having taken away what they had. Or, secondly, Because they fled away, as is usual in such cases, whilst the footmen were more easily overtaken.
Verse 11: And (1 Sam. 2:32; Ps. 78:61) the ark of God was taken; and (1 Sam. 2:34; Ps. 78:64) the two sons of Eli, Hophni and Phinehas, were slain (Heb. died).
[And the Ark of God was taken] Many greatly wonder, why God would allow His Ark to be taken, especially by the impious. But it would be more worthy of wonder, if He had not suffered it to happen. For, just as the Sabbath was made for man, not man for the Sabbath; so the Ark, sacrifices, etc., were instituted for the salvation of men. But they had prophaned those, with the result that those things were no longer serving their salvation, nor the divine glory. Thus the end for which they had been instituted failed (Martyr). Just as the Ark of the law does not defend transgressors of the law; so neither does it suffer itself to be defended by transgressors of the law. God permitted this; either, 1. Because the Hebrews had taken it out of the Sanctuary against the will of God. 2. So that the despisers of the Ark might be deprived of the Ark. 3. Lest the sacred places be thought of as future strongholds for the sacrilegious and wicked. 4. So that is might be a sign, both of Christ, to be delivered into the hands of the Jews; and of faith, to be transferred from the Jews to the Gentiles (Mendoza). 5. So that He might teach the Hebrews living rightly to trust in the providence of God. 6. So that the Philistines taking the Ark might acknowledge its force and power because of the coming plagues (Lapide out of Procopius). 7. So that He might punish the impiety of the sons of Eli (Lapide).
The ark of God was taken; which God justly and wisely permitted; partly, to punish the Israelites for their profanation of it; partly, that by taking away the pretences of their foolish and impious confidence, he might more deeply humble them, and bring them to true repentance; partly, that the Philistines might by this means be more effectually convinced of God’s almighty power, and of their own and their gods’ impotency, and so a stop might be put to their triumphs and insultations, and to their rage against the poor Israelites, whom otherwise in human appearance they might easily have rooted out. Thus as God was no loser by this event, so the Philistines were no gainers by it; and Israel, all things considered, received more good than hurt by it, as we shall see.
 Hebrew: וַיִּלָּחֲמ֣וּ פְלִשְׁתִּ֗ים וַיִּנָּ֤גֶף יִשְׂרָאֵל֙ וַיָּנֻ֙סוּ֙ אִ֣ישׁ לְאֹהָלָ֔יו וַתְּהִ֥י הַמַּכָּ֖ה גְּדוֹלָ֣ה מְאֹ֑ד וַיִּפֹּל֙ מִיִּשְׂרָאֵ֔ל שְׁלֹשִׁ֥ים אֶ֖לֶף רַגְלִֽי׃  Hebrew: וַאֲר֥וֹן אֱלֹהִ֖ים נִלְקָ֑ח וּשְׁנֵ֤י בְנֵֽי־עֵלִי֙ מֵ֔תוּ חָפְנִ֖י וּפִֽינְחָֽס׃  Hebrew: מֵתוּ.  Mark 2:27.