This syntactic reversal is a form of hyperbaton and known by another name, transferred epithet.
Syntax is concerned with word order or what one book calls, "sentence construction."
E.W. Bullinger gives these two examples of hypallage and many others:
Galatians 6:1.-"The spirit of meekness": i.e., meekness of spirit.
Ephesians 1:9.-"The mystery of His will."
For the second example, Bullinger explains:
The word μυστήριον (musteerion) rendered mystery always means a secret. And here it is the Secret pertaining to God's purpose: i.e., the Secret which He hath purposed; or, by the figure Hypallage, His Secret purpose, because the noun in regimen is the word qualified instead of the word which qualifies.
On the other hand, Georg Benedikt Winer strenuously attempts to refute the notion that any genuine examples of hypallage appear in the Greek New Testament. He thinks no example normally offered by commentators is unquestionable including Ephesians 2:2; 3:2.