Musnad Ahmad 1156:42

'Affan narrated to us, Hammad ibn Salamah narrated to us, he said: Hisham ibn 'Urwah narrated to us, from 'Awf ibn al-Harith, from his sister Rumaythah bint al-Harith, from Umm Salamah, that the wives of the Prophet, may Allah bless him and grant him peace, said to her: "Indeed, the people seek to time their gifts [to coincide with the day the Prophet is with 'Aishah]." Then he mentioned its meaning.