Musnad Abu Ya'la al-Mawsili 6:61

Abu Khaythama narrated to us, Isma'il bin Abi Uways narrated to us, my father narrated to us, from Sharik bin 'Abdullah bin Abi Namir—and he is one of the Banu al-Harith bin 'Abd Manaf bin Kinana—he said: 'Amir bin Sa'd bin Abi Waqqas informed me that his father, when he saw the disagreement of the companions of the Messenger of Allah (may Allah bless him and grant him peace) and their division, bought livestock for himself, then went out and secluded himself with his family at a water source called Qulhi. He said: Sa'd was among the sharpest of people in vision. One day, he saw something moving, so he said to those who were with him, "Do you see anything?" They said, "We see something like a bird." He said, "I see a rider on a camel." Then, after a short while, 'Umar bin Sa'd came on a Bactrian camel (or a female Bactrian camel). Then he (Sa'd) said, "O Allah, we seek refuge in You from the evil of what he has brought." 'Umar greeted him, then said to his father, "Are you content to follow the tails of these livestock among these mountains while your companions are disputing over the affair of the Ummah?" Sa'd bin Abi Waqqas said, "I heard the Messenger of Allah (may Allah bless him and grant him peace) say: 'There will be tribulations after me—or he said: affairs—in which the best of people is the one who is wealthy, hidden, and pious.' So if you are able, my son, to be like that, then be so." 'Umar said to him, "Do you have nothing other than this?" Sa'd said, "No, my son." 'Umar jumped to mount his camel, and he had not yet dismounted from it. Sa'd said to him, "Wait until we give you lunch." He said, "I have no need of your lunch." Sa'd said, "Then we shall milk for you and give you to drink." He said, "I have no need of your drink." Then he mounted and departed from his place.