Musnad Ahmad 27:1714

Isma'il ibn 'Umar narrated to us, Malik—meaning Ibn Anas—narrated to us, from Qatan ibn Wahb, from Yahnas, that a freedwoman of Ibn 'Umar came to him and said: "Peace be upon you, O Abu 'Abd al-Rahman." He said: "What is your matter?" She said: "I intended to go out to the countryside (al-rif)." He said to her: "Sit down, for I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: 'No one bears its hardship and its severity except that I will be a witness for him, or an intercessor, on the Day of Resurrection.'"