17:8 Then came Amalek. The Amalekites were a powerful and notoriously cruel people that were frequently at war with the nation of Israel. The only Amalek mentioned in the Bible was a grandson of Esau (Genesis 36:12). But that this Amalek was the ancestor of the Amalekite nation is doubtful in view of the reference to them in the time of Abraham (Genesis 14:7). There are some who have argued (Velikovsky, Courville, etc.) that these were none other than the Hyksos (a name supposedly meaning “shepherd-kings”), and that they were on their way toward invading Egypt when they encountered the fleeing Israelites. According to this scenario, it was the plagues and the destruction of Pharaoh’s army that enabled them to conquer Egypt and to rule there for two hundred years or more.

17:9 Joshua. This is the first reference to Joshua. Evidently he was already recognized by Moses as the probable future leader in the coming war of conquest in Canaan.

17:10 Hur. Little is known about Hur, except that he was a faithful aide to Moses, along with Moses’ brother Aaron (Exodus 24:14). It is possible he was Miriam’s husband, at least according to an uncertain Jewish tradition.

17:14 in a book. This is the first reference to Moses actually writing down the events that were transpiring. There are a number of other such references throughout the last four books of the Pentateuch (e.g., Numbers 33:2). Although this is the first specific command of God to write His words down in a book, there is a much earlier reference to “the book of the generations of Adam” (Genesis 5:1). See also Exodus 24:4; 34:27.

17:14 remembrance of Amalek. The Amalekites, whoever they were, continued in existence until well into the period of Israel’s kings, possibly even to the time of Hezekiah (I Chronicles 4:43). Eventually they vanished, so completely that none today can even be certain who they were.

17:15 Jehovah-nissi. The name of Moses’ altar, commemorating this initial victory over the Amalekites, means “The Lord is my banner.”