It does not follow that they had known him before and recognized his voice, though it may be so. But the Hebrew text equally supports the meaning t…

By the house of Micah.— Literally, with — that is, lodging in it, as in Genesis 27:43.

They knew…

When they were by the house of Micah
At their inn, which might be next to it, or as they were passing by it:

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The Danites determined to take Micah's gods with them. Oh, the folly of these Danites! How could they imagine those gods would protect them, when t…