Musnad Abu Ya'la al-Mawsili 7:3

Abu Khaythama narrated to us, Ma'n ibn 'Isa narrated to us, Malik ibn Anas narrated to us, from Ibn Shihab, from 'Abd al-Hamid ibn 'Abd al-Rahman ibn Zayd ibn al-Khattab, from 'Abd Allah ibn al-Harith ibn Nawfal, from 'Abd Allah ibn 'Abbas: That 'Umar ibn al-Khattab set out for al-Sham. When he reached Sargh, the commanders of the armies—Abu 'Ubaydah ibn al-Jarrah and his companions—met him and informed him that the plague had broken out in al-Sham. 'Umar said, "Call the early Muhajirun for me." They were called for him, and he consulted them. Some of them said, "You have set out for a matter, and we do not think you should turn back." Others said, "You have with you the rest of the people and the companions of the Messenger of Allah (may Allah bless him and grant him peace), and we do not think you should lead them into this plague." He said to them, "Withdraw from me." Then he said, "Call the Ansar for me." They were called for him, and he consulted them. They followed the path of the Muhajirun and differed just as they had differed. He said, "Stand up and leave me." Then he said, "Call for me those who are here from the elders of Quraysh from the Muhajirun of the Conquest." They were called for him, and he consulted them. Not two men differed with him; they said, "We think you should return with the people and not lead them into this plague." So 'Umar announced, "I am departing in the morning on my mount, so prepare yourselves." Abu 'Ubaydah said, "Is it fleeing from the decree of Allah?" 'Umar said, "If only someone other than you had said it, O Abu 'Ubaydah! Yes, we are fleeing from the decree of Allah to the decree of Allah. Do you see, if you had camels and they descended into a valley with two slopes, one fertile and the other barren, would you not, if you grazed them on the fertile one, graze them by the decree of Allah, and if you grazed them on the barren one, graze them by the decree of Allah?" Then 'Abd al-Rahman came, for he had been absent for some of his needs, and said, "I have knowledge of this. I heard the Messenger of Allah (may Allah bless him and grant him peace) say: 'If you hear of it in a land, do not enter it, and if it breaks out in a land while you are in it, do not leave it, fleeing from it.'" So 'Umar praised Allah, then turned back.