Abu Dawud Book 20, Hadith Number 3720.
Chapter : Blowing in a drink and breathing into it.
Narated By ‘Abd Allah b. Busr from Banu Sulaim : The Apostle of Allah (may peace be upon him) came to my father and he was a guest with him. He offered food to him and he brought bais. He then brought a drink which he drank and he gave it to the one on his right. He ate dried dates and began to put the kernels on the back of his ring finger and middle finger. When he got up, my father also got up, and held the rein of his mount. He said: Pray to Allah for me. He said: 0 Allah, bless them in what you have provided them, forgive them, and have mercy on them.