«وَقُلْ جَاءَ الْحَقُّ وَزَهَقَ الْبَاطِلُ إِنَّ الْبَاطِلَ كَانَ زَهُوقًا»
Say: truth has come and falsehood has vanished; falsehood is bound to vanish.
This is Qurʾān 17:81. The first part announces a particular triumph of truth; the final clause expresses a general principle that supports and strengthens that announcement.
Tadhyīl (التذييل) appends a confirming statement whose scope can be broader than the specific earlier claim. It is not simply another unrelated report, but a reinforcement that gives the first statement the force of a wider maxim.