Musnad Ahmad 1156:251

Waki’ narrated to us, Isma’il ibn ‘Abd al-Malik narrated to us, from ‘Abd al-‘Aziz, the son of the daughter of Umm Salamah, from Umm Salamah, that it reached her that the Prophet, peace and blessings of Allah be upon him, said: "There is no one among the Muslims who is afflicted with a calamity, and then says: 'To Allah we belong, and to Him we shall return. O Allah, reward me in my calamity, and replace it for me with something better than it,' except that it is done for him." She said: So I said this, and Allah rewarded me in my calamity. But who could replace Abu Salamah for me? When her waiting period ended, the Messenger of Allah, peace and blessings of Allah be upon him, proposed to her.