Shuʿbah narrated—through Muḥammad ibn ʿUbayd Allāh—from al-Ḥārith ibn ʿAmr al-Thaqafī, who said:
Our companions related to us—from Muʿādh—who said:
When the Prophet ﷺ sent me to Yemen he asked, “How will you decide if a legal case is brought before you?” I replied, “I will judge (1) according to the Book of Allah; if I find no ruling there, then according to what the Messenger of Allah ﷺ has decided.” He said, “And if you find nothing in the decisions of the Messenger?” I answered, “I will apply my own reasoning and spare no effort.” Thereupon he struck my chest and said, “Praise be to Allah who has guided the envoy of the Messenger of Allah ﷺ to that which pleases the Messenger of Allah.” (2)

Abū al-Yamān reported—Safwān ibn ʿAmr—on the authority of Rāshid ibn Saʿd, from ʿĀṣim ibn Ḥumayd al-Sakunī:
When the Prophet ﷺ dispatched Muʿādh ibn Jabal to Yemen, he walked alongside his mount while advising him. When he had finished he said, “O Muʿādh! You may not meet me again after this year, and perhaps you will pass by my mosque and my grave.” (3) Muʿādh wept bitterly at the prospect of parting from the Messenger of Allah. He said, “Do not weep, O Muʿādh—or indeed, weeping comes from Satan.” (4)

Saʿīf ibn ʿUmar said: Sahl ibn Yūsuf narrated to us—from his father—from ʿUbayd ibn Ṣakhr—that when the Prophet ﷺ bade Muʿādh farewell he said, “May Allah protect you from what is before you and behind you, and ward off …”