Matthew Poole and continuators on 1 Samuel 6:21

21 ¶ And they sent messengers to the inhabitants of Kirjath-jearim , saying, The Philistines have brought again the ark of the LORD: come ye down and fetch it up to you.

Whither they sent, either because the Place was not far off from them, and so it might soon be removed, which they mainly desired: or, because it was a place of Eminency and Strength, and somewhat further distant from the Philistines, where therefore it was likely to be better preserved from any new attempts of the Philistines, and to be better attended by the Israelites, who would more freely and frequently come to it at such a place, than in Bethshemesh, which was upon the border of their Enemies Land: or because they thought they would gladly receive it, being a pious and zealous People: or because it was in the way to Shilo, its ancient Habitation; and whither they might suppose it was to be carried by degrees, and several Stages, whereof this was one.