In Psalm 28:8 there is a great example of synthetic parallelism that brings out the connection between the people and the Lord's anointed one (Heb. מָשִׁיחַ; mashiakh). "YHWH is the strength of his people, a fortress of salvation for his anointed one."
He is their strength and a fortress for his Messiah. The two are bound together; what the LORD is to the King, he is to the people. He represents them and they are incorporated into him.
You get similar ideas in Psalm 84:9 and in Psalm 89:38ff, all preparing the way for the representative and incorporative language of the NT as it speaks of Messiah and his people.
