Havamal

Inquire and impart should every man of sense, who will be accounted sage. Let one only know, a second may not; if three, all the world knows.

Snapir ok gnapir er til sævar kømr örn á aldinn mar svá er maðr er með mörgum kømr ok á formælendr fá

Havamal: 62, Gestaþáttr