And of Zebulun he said,
Rejoice, Zebulun, in your going out;
And, Issachar, in your tents.
They shall call the peoples to the mountain;
There shall they offer sacrifices of righteousness:
For they shall suck the abundance of the seas,
And the hidden treasures of the sand.
Zebulun and Issachar could rejoice in their expansion (their going out) and in their oneness in alliance and brotherhood (‘in your tents', compare Genesis 9:27). They would be a godly people and encourage their brethren to worship Yahweh. Or ‘the peoples' may signify visiting traders. The mountain on which they would at this stage offer sacrifices of righteousness (and therefore sacrifices offered in the way that Yahweh had laid down) would be the mountain on which the Central Sanctuary would be based and where Yahweh would be worshipped. It was assumed that its establishment would be connected with a mountain, as it was in Deuteronomy 27. Or ‘the mountain' may signify “the mountain of Yahweh's inheritance” (Exodus 15:17), that is, the whole of Israel's possession. And they would rejoice in this way because of their abounding prosperity, through trade by both sea (the abundance of the seas) and land (the hidden treasures of the sand, trade through the desert or the hidden harvests of the seashore), which would explain the multitude of their thanksgiving and freewill offerings. (Compare here Genesis 49:13).
Zebulun was closely connected with ships in Genesis 49:13. It seems probable that in Egypt they had taken great interest in maritime affairs, and Moses knows of their interest and confirms that it will continue. In the event their portion was not on the coast, but their interest may well have continued through trade, and an interest in seafaring. The hidden treasures of the sand may refer to the ‘harvests' that could be reaped on the seashore of sand, shellfish, and so on, which others may have taken no interest in but which Zebulun were prepared to harvest. (A people can be landlocked and yet be interested in the sea).
Zebulun and Issachar would later be connected with Galilee (Nazareth was in Zebulun) from whence would come the Saviour of the world who would offer the greatest sacrifice of righteousness of all time. He especially, with His followers who were mainly from that area, would call men to the mountain of God as described in Isaiah 2:1-4.