Rabbi Pinchas ben Ya’ir (second century) was on his way to the House of Study, his disciples following behind him, when they came to a raging river.
He said to the river: “What are you accomplishing by preventing me from proceeding to the House of Study?”
The waters withdrew and he passed over the river safely. When he reached the other side, his disciples shouted to him: “Master, may we, too, cross over?”
He shouted back: “Any amongst you who has never insulted another creature may cross over without danger.”
——- Jerusalem Talmud, D’mai 1:3