The Messenger of Allah ﷺ said: A single rider is a devil, and a pair of riders are a pair of devils, but three are a company of riders. (Using translation from Abū Dāʾūd 2607)  

أَنَّ رَسُولَ اللهِ ﷺ قَالَ «الرَّاكِبُ شَيْطَانٌ وَالرَّاكِبَانِ شَيْطَانَانِ وَالثَّلَاثَةُ رَكْبٌ»  

[Machine] The Messenger of Allah ﷺ said, "If people knew the blessings of solitude, no traveler would ever journey by night."  

قَالَ رَسُولُ اللهِ ﷺ «لَوْ يَعْلَمُ النَّاسُ مَا فِي الْوَحْدَةِ مَا سَارَ رَاكِبٌ بِلَيْلٍ أَبَدًا»  

That the Messenger of Allah ﷺ said: "If the people knew what I know about being alone, then a rider would not journey at night." - meaning alone. (Using translation from Tirmidhī 1673)   

عَنِ النَّبِيِّ ﷺ قَالَ «لَوْ يَعْلَمُ النَّاسُ مِنَ الْوَحْدَةِ مَا أَعْلَمُ مَا سَارَ رَاكِبٌ وَحْدَهُ بِلَيْلٍ»