tn “become wise by understanding”; Grk “understanding.” The imperative “be wise” is apparently implied by the construction of vv. 15-21. See the following text-critical note for discussion.

tc ‡ The best witnesses read the imperative here (so Ì⁴⁶ א A B P 0278 33 81 1739 pc). The participle is found primarily in the Western and Byzantine texttypes (D² Ψ 1881 Ï latt [D* F G are slightly different, but support the participial reading]). But the participle is superior on internal grounds: The structure of v. 17 almost requires an imperative after ἀλλά (alla), for this gives balance to the clause: “Do not become foolish, but understand…” If the participle is original, it may be imperatival (and thus should be translated just like an imperative), but such is quite rare in the NT. More likely, there is an implied imperative as follows: “Do not become foolish, but become wise, understanding what the will of the Lord is.” Either way, the participle is the harder reading and ought therefore to be considered original. It is significant that seeing an implied imperative in this verse affords a certain symmetry to the author’s thought in vv. 15-21: There are three main sections (vv. 15-16, v. 17, vv. 18-21), each of which provides a negative injunction, followed by a positive injunction, followed by a present adverbial participle. If συνίετε (suniete) is original, this symmetry is lost. Thus, even though the external evidence for συνιέντες (sunientes) is not nearly as weighty as for the imperative, both the transcriptional and intrinsic evidence support it.