This story comes from Shogun and Samurai: Tales of Nobunaga, Hideyoshi, and Ieyasu by Okanoya Shigezane (1835-1919). The text is translated by Andrew and Yoshiko Dykstra.
"Once, when Nobunaga was playing in the yard, a small snake appeared. Grasping it in his hands, Nobunaga asked one of his attendants, 'Do you call my action brave?' The attendant replied, 'You don't need to be afraid of such a small snake.' The young Nobunaga asked again, 'The size of the snake has nothing to do with its poison. If you are not afraid of a snake because it is small, then do you disdain your lord if he is young and small?' At this, the attendant was most embarrassed."
Very clever by Nobunaga. It just goes to show that Nobunaga and most of the Sengoku warlords had much more common sense back then. It would be great if any of our modern leaders today had any common sense like Nobunaga and others had during Sengoku Japan.
Tenka no tame!