Musnad Ahmad 1201:1

Hashim ibn al-Qasim narrated to us, he said: al-Mas'udi narrated to us, from 'Abd al-Malik ibn 'Umayr, from a man of the family of Abu Hathmah, from al-Shifa' bint 'Abd Allah, and she was a woman from the emigrants (Muhajirat), she said: The Messenger of Allah, peace and blessings of Allah be upon him, was asked about the best of deeds. He said: "Faith in Allah, and Jihad in the way of Allah, the Almighty and Majestic, and an accepted Hajj."