«نَهَارِ الْعَدُو مَا يِصْفَى يِخْفَى»

The saying claims that an enemy never becomes truly sincere. It exaggerates the point by imagining a day when the foe's heart turns clear, meaning pure and reconciled rather than anything about weather, and then declaring that such a day simply vanishes. Real goodwill from an adversary is treated as something that cannot exist.

Some speakers turn the line into a curse instead of an observation, wishing the day of the enemy's apparent friendliness to disappear and never return. The wording alone does not always show which reading a speaker means. Either way, the speaker wants nothing from that person, not even a show of goodwill.

Say it when someone warns against trusting a sudden show of friendliness from an established opponent. It can also serve as a sharp dismissal, rejecting any reconciliation with that person. It is dismissive, so it suits talk among allies rather than remarks made to the adversary.