الْقَلْبُ
Inverting the expected relation or placement of two parts of an expression.
Qalb is another form of departure from expected wording. A normal relation between two parts of an utterance is presented in reversed form, while the context still allows the audience to recover the intended meaning.
Inversion is not always commendable. If it merely corrupts the meaning and offers no discernible literary point, it cannot count as successful rhetoric. The source also reports disagreement about the unconditional acceptability of this device.