The angels know our prayers because they carry them to God's throne. There are numerous text-proofs in the Book of Revelation. It is written: "Then another angel, having a golden censer, came and stood at the altar. And he was given much incense, that he should offer it with the prayers of all the saints upon the golden altar which was before the throne. And the smoke of the incense, with the prayers of all the saints, ascended before God from the angel's hand" (Rev.8: 3,4). Here we see the prayers of the saints ascending before God from the angel's hand and censer. So how can the angels not know our prayers?