He that backbites not with his tongue, nor does evil to his neighbor, nor takes up a reproach against his neighbor.
All Commentaries on Psalms 15:3 Go To Psalms 15
Augustine of Hippo
AD 430
3. "Who speaketh the truth in his heart." For some have truth on their lips, and not in their heart. As if one should deceitfully point out a road, knowing that there were robbers there, and should say, If you go this way, you will be safe from robbers; and it should turn out that in fact there were no robbers found there: he has spoken the truth, but not in his heart. For he supposed it to be otherwise, and spoke the truth in ignorance. Therefore it is not enough to speak the truth, unless it be so also in heart. "Who hath practised no deceit in his tongue" (ver. 3). Deceit is practised with the tongue, when one thing is professed with the mouth, another concealed in the breast. "Nor done evil to his neighhour." It is well known that by "neighbour," every man should be understood. "And hath not entertained slander against his neighbour," that is, hath not readily or rashly given credence to an accuser.
