Sahih Bukhari
Merits of the Helpers in Madinah (Ansaar)
Volume: 005 / Book Number: 058 / Hadith Number: 247
Narrated Al-Bara:
When the Prophet migrated to Medina, Suraqa bin Malik bin Ju'sham pursued him. The Prophet invoked evil on him, therefore the forelegs of his horse sank into the ground. Suraqa said (to the Prophet ), "Invoke Allah to rescue me, and I will not harm you. "The Prophet invoked Allah for him. Then Allah's Apostle felt thirsty and he passed by a shepherd. Abu Bakr said, "I took a bowl and milked a little milk in it and brought it to the Prophet and he drank till I was pleased."