Wisdom Can be Contagious

Later the Buddha confirmed that Moggallana was indeed a very capable speaker on the Dharma, as is evident from his discourses in the [Pali] canon. Talks on the Dharma gain in range and depth when they issue from an experience that transcends the realm of the senses. The more one has widened one’s consciousness by deep meditation and personal insight into truth, the more convincing one’s words will be, and when one can speak from the heights of wisdom, one’s understanding will be contagious.
from Great Disciples of the Buddha