SHAFAQNA – It is narrated that the Roman Caesar wrote a letter to Imam Ali (AS) in which he complained about a headache he was having and the doctors were unable to cure it. Imam Ali (AS) sent a hat to him and ordered: Whenever you get headache, put this hat on, and you will be relieved from it. When the Roman Caesar followed the instruction, by the will of God he was cured. This was amazing for the Roman Caesar and he ordered to open the hat and see what is inside it. They opened the hat and noticed a piece of paper which was written on it: “Besmellah-e-Rahman-e-Rahim; meaning, in the Name of Allah (SWT), the Most Compassionate, the Most Merciful.” When the Roman Caesar found out that his cure was due to this blessed name, he converted to Islam, but he kept hidden his conversion to Islam [1].
[1] Tafseer Menhajul Sadiqeen,Vol. 1, page 33.