Though they say, The Lord liveth; though when they swear, they use the form of an oath, and say, The Lord liveth, Jeremiah 5:2, or, By the living God. By swearing here we may understand all their service of God, by a synecdoche, swearing being a part of God's worship. Surely they swear falsely; yet, or therefore, they swear falsely; either they swear to that which is false; or if to that which is true, they are so perfidious to me, that they do it deceitfully, not in sincerity, and in reverence to that holy name by which they swear: possibly they may often speak of God, and not swear by false gods, Jeremiah 5:7, but it is all but hypocrisy and deceit, Isaiah 48:1 Jeremiah 12:2, Jeremiah 42:5,20 2 Timothy 3:5. It is neither in truth nor righteousness, two of the principal qualifications of a lawful oath. Thus they prostitute the name of God, making themselves guilty, not of hypocrisy only, but sacrilege.
Related Commentaries of Jeremiah 5:2
Jeremiah 5:2
2 And though they say, The LORD liveth; surely they swear falsely.