Abu 'Abdullah bin Abul-'as (May Allah be pleased with him) reported

I complained to the Messenger of Allah (ﷺ) about a pain I had in my body. The Messenger of Allah (ﷺ) said, "Place your hand where you feel pain and say: 'Bismillah (With the Name of Allah)' three times; and then repeat seven times: 'A'udhu bi'izzatillahi wa qudratihi min sharri ma ajidu wa 'uhadhiru (I seek refuge with Allah and with His Power from the evil that afflicts me and that which I apprehend)."'

[Muslim].