9 Moses said to Joshua, “Choose men for us, and go out to fight with Amalek. Tomorrow I will stand on the top of the hill with God’s rod in my hand.” Exodus 17:9WEB
This passage contains a positive command, issued by Moses, directed toward Joshua: "Choose men for us and go out to fight with Amalek.".
This command contributes to our understanding of Prophecy; it is a statement from God's prophet, Moses.
The command was fulfilled in the passages coming after this.
Notes on Interpretation/Application
Biblical Mode for Describing Prophetic Speech
This command is noteworthy, because (unlike the majority of prior prophetic words in Exodus), it is not explicitly stated that God commanded Moses to perform the sign described here by Moses. The Bible does not here say that God told Moses, "hold up this staff, and as long as you hold it up, Israel will prevail against Amalek". However, in spite of that lack of a description of a direct word from God, we can see in verses 11-13 that God did perform the miraculous work through Moses, as described here. So, the word was spoken with the authority of God, or with God's support.
The implication here is that when Moses says "X" to Israel, the Bible doesn't have to explicitly state "God told Moses to say X to Israel" in order for X to be a legitimate statement from God to Israel.