When the Messenger of Allah ﷺ sent Muaz to Yemen, the Messenger of Allah ﷺ went out with him to give him final instructions. Muaz was riding while the Messenger of Allah ﷺ walked beneath his mount. When he finished, he said, "Muaz, perhaps you will not meet me again after this year of mine. Perhaps you will only pass by this mosque of mine or by my grave."Muaz wept out of grief at parting from the Messenger of Allah ﷺ. Then the Prophet ﷺ turned and faced toward Medina and said, "The closest of people to me are the God-fearing, whoever they may be and wherever they may be."
لما بعثه رسول الله ﷺ إلى اليمن، خرج معه رسول الله ﷺ يوصيه، ومعاذ راكب، ورسول الله ﷺ يمشي تحت راحلته، فلما فرغ قال: يا معاذ إنك عسى أن لا تلقاني بعد عامي هذا، أو لعلك أن تمر بمسجدي هذا أو قبري، فبكى معاذ جشعا لفراق رسول الله ﷺ، ثم التفت فأقبل بوجهه نحو المدينة، فقال: إن أولى الناس بي المتقون من كانوا وحيث كانوا.
Ahmad (22052, 22054) narrated it from Abu Mughira (whose name is Abdullah bin Hajjaj Khawlani), who said, our teacher Safwan (that is, Ibn Amr) narrated to us, from Rashid bin Saad, from Asim bin Humayd Sakuni, from Muaz bin Jabal, and he related it. Its chain is hasan because of Asim bin Humayd Sakuni, for his hadith is hasan.His saying, "jashaan", jasha means terror at parting from a loved one.