Of cursing; either,
1. Of oaths and blasphemies against God. Or,
2. Of reviling and execration of other men, especially those that are good; or those that stand in his way, and hinder his wicked designs. Or rather,
3. Of oaths and imprecations against himself, of which this word is used, Numbers 5:21 Deuteronomy 29:12,21 Ne 10:29; by which he endeavours to gain credit, and to make his neighbours secure, and so to make way for the deceit and fraud which here follows. For this wretched man is represented both here, and in the succeeding verses, as one that doth not act with open violence and hostility, but with subtle and secret artifices, using all cunning insinuations, and flatteries, and lies, and, among others, oaths, of which an atheistical politician said, that men were to be deceived with oaths, and children with rattles or toys. Deceit and fraud; two words signifying the same thing, to note the greatness and frequency of his deceits. Or one word may signify the deceit lurking in his heart, and the other the manifestation of it in external frauds and stratagems. Under his tongue; either,
1. In his heart, which is under the tongue. Or rather,
2. Under his fair and plausible speeches the mischief here following is hid and covered. Withal he seems to allude to serpents, whose poison lies hidden under the tongue or within their teeth. Mischief and vanity; or rather, iniquity, as this word is oft rendered, or injury, the vexation or oppression of other men, which he covers with these fair pretences.