Musnad Abu Ya'la al-Mawsili 152:260

Abu Khaythama narrated to us, Muhammad ibn Abd Allah al-Asadi narrated to us, Aban ibn Abd Allah al-Bajali narrated to us, from Karim ibn Abi Hazim, from Salma bint Jabir, that her husband was martyred. She came to Abd Allah ibn Mas’ud and said, "O Abu Abd al-Rahman, my husband has been martyred, and men have proposed to me. Do you hope that if Allah unites me and him in Paradise, I will be among his wives?" He said, "Yes." Some of the people said, "O Abu Abd al-Rahman, we have not seen you do this for any woman other than this one." He said, "I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: 'Indeed, the first of my nation to join me in Paradise is a woman from [the tribe of] Ahmas.'"