It is narrated from Hazrat Abu Saeed Khudri (may Allah be pleased with him) that once Hazrat Abu Musa Ash'ari (may Allah be pleased with him) greeted Hazrat Umar (may Allah be pleased with him) three times. He was not granted permission, so he returned. Later, when Hazrat Umar (may Allah be pleased with him) met him, he asked, "Why did you leave?" He replied, "I sought permission three times, and when I was not granted permission, I left. This is what we have been instructed to do." Hazrat Umar (may Allah be pleased with him) said, "Present a witness for this, otherwise I will punish you." Hazrat Abu Musa (may Allah be pleased with him) went to a gathering of the Ansar. They said, "Even the youngest among us can testify to this." Thus, Hazrat Abu Saeed Khudri (may Allah be pleased with him) went with them and testified to it, so Hazrat Umar (may Allah be pleased with him) let him go.