Jami` at-Tirmidhi 2070

Qatadah said:"It was narrated to me that Abu Hurairah said:'Ash-Shuniz is a cure for every disease except As-Sam.' Qatadah said: "One takes twenty-one seeds daily, and puts them in a cloth, then infuses (water) and sniffs two drops in his right nostril, and one drop in the left. The second (day) two drops are sniffed in the left, and one drop in the right. The third (day) two drops in the right and one drop in the left