Musnad Ahmad 26:76

Abu Mu'awiyah narrated to us, Ibrahim ibn Muslim al-Hajari narrated to us, from Abu al-Ahwas, from Abdullah, who said: Whoever is pleased to meet Allah, the Almighty and Majestic, tomorrow as a Muslim, let him maintain these prescribed prayers where they are called out, for they are among the paths of guidance. And indeed, Allah, the Almighty and Majestic, has legislated for your Prophet the paths of guidance. There is not one among you except that he has a prayer place in his house. If you were to pray in your houses, just as this person who stays behind prays in his house, you would have abandoned the Sunnah of your Prophet. And if you were to abandon the Sunnah of your Prophet, you would go astray. I have seen myself, and no one would stay behind from them [the congregational prayers] except a hypocrite whose hypocrisy was known. And I have seen a man being supported between two men until he was stood in the row. And the Messenger of Allah (peace and blessings of Allah be upon him) said: "There is no man who performs ablution, and perfects the ablution, then comes to one of the mosques, but for every step he takes, he is raised a degree, or a sin is removed from him, or a good deed is written for him." We used to even shorten our steps. "And the superiority of a man's prayer in congregation over his prayer alone is twenty-five degrees."