In Tobit 12:12, Raphael says,
"I can now tell you that when you, Tobit, and Sarah prayed, it was I who presented and read the record of your prayer before the Glory of the Lord; and I did the same thing when you used to bury the dead."In Revelation 8:2-5,
And I saw the seven angels who stand before God, and to them were given seven trumpets. Another angel, who had a golden censer, came and stood at the altar. He was given much incense to offer, with the prayers of all the saints, on the golden altar before the throne. The smoke of the incense, together with the prayers of the saints, went up before God from the angel's hand. Then the angel took the censer, filled it with fire from the altar, and hurled it on the earth; and there came peals of thunder, rumblings, flashes of lightning and an earthquake.This description in particular is counter-intuitive: Jews and Christians believe that God is all-knowing and all-powerful. He's not only capable of hearing our prayers directly (Genesis 21:17; Psalm 66:19), but of knowing what we're going to pray before we pray it (Matthew 6:8). He has literally no need for intermediaries - in this case, His angelic Pony Express. But yet again, our loving God deigned to include His creations in His most intimate acts, a pattern we see throughout His Creation.
It's telling that the author of Tobit (or more accurately, Raphael) records not only the seven angels standing at the Throne of God, but also their role as intermediaries of prayers. As before, this isn't information one would naturally guess, and to my knowledge, this is the only time in the Old Testament that we hear of angels as intermediaries for prayer. Once again, it would be hard to imagine stronger evidence for the idea that Tobit is an inspired book.