Musnad Ahmad 31:671

Ali ibn Ishaq narrated to us, he said: Abdullah informed us, and 'Attab said: Abdullah narrated to us, Yunus informed us, from al-Zuhri, he said: Ubaydullah ibn Abdullah narrated to me, that he heard Abu Sa'id al-Khudri saying: I heard the Messenger of Allah, peace and blessings of Allah be upon him, forbidding the turning of the mouths of water skins inside out.