The Messenger of Allah ﷺ said, "A lone rider is a devil, two riders are two devils, and three are a travelling party."
حدثنا عبد الله بن مسلمة القعنبي
قال رسول الله ﷺ الراكب شيطان والراكبان شيطانان والثلاثة ركب
[Its chain of transmission is hasan] Tirmidhi narrated it in jihad, chapter on the dislike of a man traveling alone, h: 1674, from the hadith of Malik through this route, and he said, "Hasan." It is also found in the Muwatta (Yahya): 978/2. Hakim graded it sahih in 2/102, and Dhahabi agreed with him. Baghawi graded it hasan in Sharh al-Sunnah, h: 2675.