is the man who deceives his neighbor and says, “I am only joking!”
See here, 1. How mischievous those are that make no scruple of deceiving their neighbours; they are as madmen that cast firebrands, arrows, and death, so much hurt may they do by their deceits. They value themselves upon it as polite cunning men, but really they are as madmen. There is not a greater madness in the world than a wilful sin.
Commenting on Proverbs 26:18-19
So is the man that deceiveth his neighbour,.... By telling him a lie; or by reporting false things concerning him; or by cheating him in trade and commerce; or by taking his goods privately from him; and, when caught in either of these, and saith, Am not I in sport?
So [is] the man [that] deceiveth his neighbour, and saith, Am not I in sport? (i) Who disguises himself to be that which he is not.