Musnad Abu Ya'la al-Mawsili 110:210

Ubayd Allah ibn Umar ibn Maysarah narrated to us, Khalid ibn al-Harith narrated to us, Sa'id narrated to us, from Qatadah, from Abu Nahik, from Ibn Abbas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever asks you by the Face of Allah, then give to him. And whoever seeks refuge with you by Allah, then grant him refuge."