John Trapp on Ephesians 5:17

Verſe 17. But underſtanding what] Drawing your knowledge into practice, as verſ. 10. For the fear of the Lord that is wiſdome, and to depart from evil is underſtanding, Job 28.28. Where, wiſdome (proper to the underſtanding) is aſcribed to the will, becauſe practice ſhould be joyned to knowledge. Hence alſo Eccleſ. 10.2. A wiſe mans heart is at his right hand, becauſe his heart teacheth his hand to put things in practice.