“took of their provisions.” This may or may not have been part of a communal meal, where the Israelites and Gibeonites shared food together. The text does not communicate any suspicion here, although the Israelites could have had some. It seems, however, especially given the context, that Israel was simply accepting the provisions and story of the Gibeonites.
“did not ask counsel from the mouth of Yahweh.” Literally, “did not ask the mouth of Yahweh.” The literal “ask the mouth” is a metonymy, with “mouth” being put for asking for what comes from the mouth, that is, advice.
[See figure of speech “metonymy.”]