A rhetorical device, especially in the OT, using two words similar in sound or appearance. It is difficult to reproduce this Hebrew play upon words, but one suggestion for the pun in Isa. 7: 9 is ‘If you are not firm in faith, you will not be firm at all’. Proper names provide fertile ground for paronomasia: ‘Isaac’ is a play on the Hebrew verb ‘to laugh’, as is explained by Gen. 21: 6.