«الطباق: هو الجمع بين معنيين متقابلين»
Tibaq brings together two opposite or contrasting meanings.
The opposition can be lexical, affirmative versus negative, or another valid contrast. The contrasting terms need not always be adjacent; what matters is that their relationship makes one intended point sharper.
A random pair of contradictions is not automatically elegant tibaq: both sides should work toward a coherent rhetorical purpose.