Musnad Ahmad 482:167

Hassan narrated to us, Ibn Lahi'ah narrated to us, Abu Qabil narrated to us, from Abu 'Ashanah al-Ma'afiri, from 'Uqbah ibn 'Amir, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever leaves his house for the mosque, ten good deeds are written for him for every step he takes. And the one sitting in the mosque waiting for the prayer is like the devoutly obedient, and he is recorded among those who pray until he returns to his house."