Musnad Abu Ya'la al-Mawsili 109:76

Ja'far narrated to us, Ibn al-Mubarak narrated to us, from 'Utbah ibn Abi Hakim, from Husayn ibn Harmalah, from Abu al-Musabbih, from Jabir ibn 'Abd Allah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "No servant's feet become dusty in the path of Allah for an hour of a day, except that they are forbidden to the Fire."