1 Corinthians 7:25 Now concerning virgins: I have no commandment from the Lord; yet I give judgment as one whom the Lord in His mercy has made trustworthy.
A Prophet can declare not because God spoke but it happens because of the relationship he has with God. 2 Kings 1:10 So Elijah answered and said to the captain of fifty, “If I am a man of God, then let fire come down from heaven and consume you and your fifty men.” And fire came down from heaven and consumed him and his fifty.
The same way Joshua commanded the sun to stand still, Prophets of today can still declare and the favor of God upon them makes it comes to pass.
Matthew 10:41 He who receives a prophet in the name of a prophet shall receive a prophet’s reward. And he who receives a righteous man in the name of a righteous man shall receive a righteous man’s reward.