The source example has two distinct agents: al-nāhī, the one who forbids love, and al-wāshī, the informer or tale-bearer. Two distinct consequences appear in correspondence: the lover's attachment becomes stronger, and the beloved heeds the informer.
«إذا ما نهى الناهي عن حبها»
When the one who forbids her love tries to restrain it.
This illustrates the first branch of the condition. The context of tale-bearing supplies the other. The matching results create the complete double pairing. No single repeated word by itself establishes muzāwajah.