Musnad Ahmad 28:586

Qutaybah ibn Sa'id narrated to us, Ibn Lahi'ah narrated to us, from al-Qasim ibn 'Abd Allah al-Ma'afiri, from Abu 'Abd al-Rahman al-Hubuli, from al-Qasim ibn al-Barhi, from 'Abd Allah ibn 'Amr, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever brings out charity, and finds none but a Berber, let him return it."