Musnad Ahmad 26:804

Abu Qatan narrated to us, from al-Mas'udi, from 'Ali ibn al-Aqmar, from Abu al-Ahwas, from 'Abdullah, who said: "Whoever is pleased to meet Allah tomorrow as a Muslim, let him maintain these five prayers where they are called out. For Allah, the Almighty and Majestic, has legislated the paths of guidance for His Prophet, and they (the prayers in congregation) are among the paths of guidance. And I do not think there is anyone among you except that he has a place of prayer in his house where he prays. If you were to pray in your houses and abandon your mosques, you would have abandoned the Sunnah of your Prophet, may Allah bless him and grant him peace. And if you were to abandon the Sunnah of your Prophet, you would go astray."