Res Gestae

When Anastasius saw this, he began to ponder, and learning from it that none of them should rule, he began to pray to God that He would show him a sign, so that while he still lived he might know who should receive the royal power after his death. While he was considering the question with fasting and

prayer, one night in a dream he saw a man, who advised him as follows: The person whose arrival shall first be announced to you tomorrow in your bedroom will be the one to receive your throne after you.