Question: Why is Joshua first called Joshua in Exodus 17:9, but then later on in Numbers 13:16, that is when Moses changes Hoshea’s name to Joshua. What am I missing? Isn’t this out of order?
Answer: Sharp question. Most of the commentaries I saw (see the Seforno, Rashbam, Malbim, Rabbi Shamshon Rafael Hirsch) agree that Joshua was called that before also. They say it was the name that refers to his status as Moses’s servant. That was being re-stressed in Numbers to give him extra protection for the scouting mission.