“Moses commanded us a law,
An inheritance for the assembly of Jacob.
And he was king in Jeshurun,
When the heads of the people were gathered,
All the tribes of Israel together.”
“Moses.” There is no reason for doubting that in the light of his coming death Moses could in such a solemn writing speak of himself in the third person. This was intended to be a solemn record and he intended its happenings to be recorded and passed on down the generations in a way that they would understand clearly.
“He was king in Jeshurun.” Some see this as Moses declaring his status. He was ‘king' in Jeshurun, and commanded them a law. This law was the inheritance of ‘the assembly of Jacob', it was what was passed on to them from Yahweh through Moses. ‘Assembly of Jacob' indicates either the gathered Israelite leadership, the men of Israel as a whole, or the whole people.
Jeshurun (‘the upright one' - some say in the diminutive, although that is questionable) refers to the people of Israel in Deuteronomy 32:15; Isaiah 44:2. They were gathered together with their leaders as an upright nation responding to Yahweh's covenant, with Moses as ‘king' over them. In this view Moses wanted future generations to recognise the full authority that he had.
Others see ‘He was king in Jeshurun' as referring to Yahweh as King over His people, with His throne as the Ark of the Covenant of Yahweh. Compare Exodus 15:18; the suzerainty treaty - Exodus 20:1-17; Numbers 23:21; Judges 8:23. The people saw themselves as a theocratic people with Yahweh ruling over them. This is possibly the preferable way of looking at it, and we would expect the idea of Yahweh as ‘coming from Sinai' with His law, to be taken up again prior to the blessings on the tribes. It would be a way by which Moses could assure them that their future was secure. Yahweh was their everlasting King.
(There were dangers in using the title of ‘king' (melek) of Yahweh, for the god of Ammon was called Melek (becoming with the addition of the vowels from bosheth (‘shame') Molech) and there could have been confusion. This would explain why, although the covenant format revealed Yahweh as His people's Overlord, the term King was generally avoided except in a context like this).
It is possible that in the reciting of the poem at covenant festivals this section was intended to be a response of the people to the narrator, which would further explain the reference to Moses in the third person. But such a theory is not necessary.
Moses then, with the prophetic instinct of a dying prophet, spoke of the future of God's people. Something of which he said of each tribe applied to all the tribes of Israel (we can compare with this the letters to the seven churches in Revelation 1-3 which were written to seven specific churches, but were intended for all the church of Christ). Because it was necessary to maintain the number twelve, and because he intended to mention both Ephraim and Manasseh, he had to omit one tribe and he chose to omit Simeon, probably with mutual agreement as they humbly and repentantly recognised how they had failed at Baal Peor and over the Midianitish woman. But they were still included in his overall words. This omission was possibly partly because in the blessing of Jacob Simeon and Levi were included as one (they were probably twins and did everything together - compare Genesis 34:25). Here his words to Levi would not have suited Simeon apart from verse 11. Or it may have been because of a developed closeness with Judah.
The suggestion that Simeon is omitted because this was written after Simeon had disappeared as a tribe is lacking in evidence and contradicts the evidence of 1 Chronicles 12:25; 1Ch 27:16; 2 Chronicles 15:9; 2 Chronicles 34:6. At the division of the kingdoms there were still recognised to be twelve tribes excluding the Levites, and that puts Simeon among the ten, although not all in the ten seceded (2 Chronicles 15:9). The position was necessarily very complicated, and loyalties were tested. But it is clear that Simeon were still able to contribute soldiers at different periods, and that there were Simeonite cities in the time of Josiah