When we were on a journey with the Prophet a nomadic Arab approached, and when he came near God's messenger said to him, "Do you testify that there is no god but God alone who has no partner and that Muhammad is His servant and messenger?" He asked, "Who will testify to what you say?" Replying, "This mimosa tree," he called it. It was at the side of the wadi, and it came forward furrowing the ground till it stood in front of him. He asked it to testify three times, and when it had testified three time that it was as he had said, it returned to its said. Darimi transmitted it.