وَفَى خَالِدٌ بِعَهْدِهِ؛ وَالْوَفَاءُ مِنْ شِيَمِ الْكِرَامِ.
Khalid kept his pledge; fidelity is among the virtues of noble people.
The first sentence reports a particular event; the second supports it with a more general principle. The later sentence is meaningful independently, which makes this a useful example of explanatory epilogue or tadhyīl.
Not every repetition is tadhyīl, and not every generality strengthens the preceding statement. A sound classification explains both the reinforcing relation and the movement toward a broader maxim.