Moses is standing at the shore of the Red Sea. The Egyptians are closing in. A dispute arises as to what to do next, which Moses takes some time to resolve. He leads them in prayer, and then continues to pray, saying:
“O Lord of the world! I am like the shepherd who, having undertaken to pasture a flock, has been heedless enough to drive his sheep to the edge of a precipice, and then is in a despair how to get them down again…”
He goes on at some length. “But God cut short his prayer, saying: “Moses, My children are in distress-the sea blocks the way before them, the enemy is in hot pursuit after them, and thou standest here and prayest. Sometimes long prayer is good, but sometimes it is better to be brief.”
I had such a laugh at that. And it happens several more times, as Moses attempts to part the Red Sea and the sea argues with him, and he then talks to God again, who explains again what to do, and so on, repeating several more times “Don’t just stand there praying, Moses!!”
This is from Legends of the Jews by Louis Ginsberg. I love exactly this aspect of the tales, for they show such an intimacy with God.