In literary criticism and rhetoric, a tautology is a statement that repeats an idea using near-synonymous morphemes, words or phrases, effectively "saying the same thing twice".
[4] The word was coined in Koine Greek from ταὐτός ('the same') plus λόγος ('word' or 'idea'), and transmitted through 3rd-century Latin tautologia and French tautologie.
This is related to the rhetorical device of hendiadys, where one concept is expressed through the use of two descriptive words or phrases: for example, using "goblets and gold" to mean wealth, or "this day and age" to refer to the present time.
Superficially, these expressions may seem tautological, but they are stylistically sound because the repeated meaning is just a way to emphasize the same idea.
Much Old Testament poetry is based on parallelism: the same thing said twice, but in slightly different ways (Fowler describes this as pleonasm).