Prove all things; hold fast that which is good.
Ver. 21. Prove all things] Take nothing that you hear upon trust (Νηφε και μεμνησο απιστειν, Epicharm.), but bring all to the test, Isaiah 8:20. To the law, i.e. the Old Testament, and to the testimony, i.e. the New, which is by St John often called the testimony. Mercer observes that of the Hebrew word ozen for an ear, cometh Moznaiim for a pair of balances; to note that we must weigh what we hear; our two ears must be as balances for that purpose.
Hold fast that which is good] Orthodox, current, agreeable to, and approvable by, the Scriptures, especially that which God hath made good and sweet to your own souls. Hold fast that thou hast, &c. Hast thou found honey? eat it, Proverbs 25:16. Go on to heaven eating of it, as Samson did of his honeycomb.