Commentaries:
At first glance, it appears that "oracle" here means the message—God's revelation concerning this or that. While that is not a wrong understanding, it is a bit too simplistic: We do not inquire at a message; we inquire of, in, or from a message. The various literal translations of God's Word confirm that "at" is in fact the correct preposition. We inquire at a place. Thus, the oracle is a place where a message is spoken.
Charles Whitaker
The Oracles of God