Abu Dawud Book 22, Hadith Number 3866.

Narated By Sa’d : I suffered from an illness. The Apostle of Allah (PBUH) came to pay a visit to me. He put his hands between my nipples and I felt its coolness at my heart. He said: You are a man suffering from heart sickness. Go to al-Harith ibn Kaladah, brother of Thaqif. He is a man who gives medical treatment. He should take seven ajwah dates of Medina and grind them with their kernels, and then put them into your mouth.