Dating the psalms
Unlike poetry that relies on rhyme, parallelism can be translated into other languages without losing its distinct flavor.
The two basic types of parallelism are: Synonymous Parallelism is the most common form of parallelism.
A second common characteristic of Hebrew poetry is its use of imagery, comparing one thing to another.
Of course, imagery can be found in prose sections of the Old Testament and it is not found in every psalm, but it is especially rich in Hebrew poetry.
The power and beauty of the 23rd Psalm is the way that it communicates these ideas through images: shepherd/sheep, green pastures/still waters, the valley of the shadow of death, a table, an anointing, and an overflowing cup.
But scholars have realized rather recently that synonymous parallelism is something of a misnomer. You might describe it as "A, what's more B." The second line always seems to carry forward the thought found in the first phrase in some way.
This progression is sometimes subtle, but often quite obvious.
And then, when he was but a teenager, the Prophet Samuel came to his family's farm and poured oil over his head, anointing David King of Israel.
From that moment the Holy Spirit of God poured over him as well.