The Bible tells us:
"If anyone speaks, [his speech should be] like the oracles of God;
if anyone serves, [his service should be] from the strength God provides, so that in everything God may be glorified through Jesus Christ. To Him belong the glory and the power forever and ever. Amen. (1 Peter 4:11 - Holman Christian Standard Bible)
I've noticed a lot of people desire and pray to speak as the "oracles of God" especially when they are preaching. There is nothing wrong with that prayer - once you realise that the key to speaking as an oracle is in first being a receptacle of God's word.
The other thing about being an oracle is to be careful that you are not just an orator - there is a sharp difference between them. Apollos is an example of an orator. Acts 18: 24-26 puts it this way: "At that time a Jew named Apollos, who had been born in Alexandria, came to Ephesus. He was an eloquent speaker and had a thorough knowledge of the Scriptures.He had been instructed in the Way of the Lord, and with great enthusiasm he proclaimed and taught correctly the facts about Jesus. However, he knew only the baptism of John. He began to speak boldly in the synagogue. When Priscilla and Aquila heard him, they took him home with them and explained to him more correctly the Way of God." (GNT)
The flip side to that is: God can use any creature* as his oracle...yes, there is precedent.
Numbers 22: 28-31: Then the Lord gave the donkey the ability to speak. “What have I done to you that deserves your beating me three times?” it asked Balaam. “You have made me look like a fool!” Balaam shouted. “If I had a sword with me, I would kill you!” “But I am the same donkey you have ridden all your life,” the donkey answered. “Have I ever done anything like this before?” “No,” Balaam admitted. Then the Lord opened Balaam’s eyes, and he saw the angel of the Lord standing in the roadway with a drawn sword in his hand. Balaam bowed his head and fell face down on the ground before him." (NLT)
Note that the donkey didn't just blabber - it had a very intelligent conversation with Balaam. So if a donkey can speak so sensibly, we must never think too highly of ourselves as oracles of God. As one of my senior pastor's said: "Check yourself because even an ass can speak."