Musnad Abu Ya'la al-Mawsili 154:103

Zuhayr narrated to us, Waki' narrated to us, 'Abdullah ibn Nafi' informed me, from his father, from Ibn 'Umar: That the Prophet (ﷺ) was brought *jar fadikh* (a beverage made from unripe dates) while he was in the Mosque of Fadikh, so he drank it. And for that reason, it was named the Mosque of Fadikh.