Adam Clarke on Ephesians 4:25

Wherefore putting away lying - All falsity, all prevarication, because this is opposite to the truth as it is in Jesus, Eph 4:21, and to the holiness of truth, Eph 4:24.

Speak every man truth with his neighbor - Truth was but of small account among many of even the best heathens, for they taught that on many occasions a lie was to be preferred to the truth itself. Dr. Whitby collects some of their maxims on this head. Κρειττον δε ελεσθαι ψευδος, η αληθες κακον· "A lie is better than a hurtful truth." - Menander. Το γαρ αγαθον κρειττον εστι της αληθειας· "Good is better than truth." - Proclus. Ενθα γαρ τι δει και ψευδος λεγεσθαι, λεγεσθω. "When telling a lie will be profitable, let it be told." - Darius in Herodotus, lib. iii. p. 101. "He may lie who knows how to do it εν δεοντι καιρῳ, in a suitable time." - Plato apud Stob., ser. 12. "There is nothing decorous in truth but when it is profitable; yea, sometimes και ψευδος ωνησεν ανθρωπους, και τ' αληθες εβλαψεν, truth is hurtful, and lying is profitable to men." - Maximus Tyrius, Diss. 3, p. 29.

Having been brought up in such a loose system of morality, these converted Gentiles had need of these apostolic directions; Put away lying; speak the truth: Let lying never come near you; let truth be ever present with you.

We are members one of another - Consider yourselves as one body, of which Jesus Christ is the head; and as a man's right hand would not deceive or wrong his left hand, so deal honestly with each other; for ye are members one of another.