Yusayr bin Amr (may Allah be pleased with him) said: Sayyiduna Abu Mas'ud al-Ansari (may Allah be pleased with him) set out in this direction, and I went out with him until, when we reached al-Saylahin, he dismounted and I dismounted with him. When I saw that he was alone, I went up to him and said: "O Abu Mas'ud, there were three of the Companions of Muhammad (peace and blessings be upon him) among us: as for Hudhayfah, he has died; as for Abu Musa, he has gone to Syria; and you have set off in this direction, while trials have occurred as you see." He said to me: "O Yusayr, I am your sincere well-wisher: hold firmly to the community, for Allah will not gather the Ummah of Muhammad (peace and blessings be upon him) upon misguidance, until a righteous man finds rest or rest is found from a wicked man."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 14739