Sahih Adab al-Mufrad

It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that when the Prophet (peace and blessings of Allah be upon him) would visit a sick person, he would sit near his head and then say this seven times: «أسأل الله العظيم ، رب العرش العظيم أن يشفيك» "I ask the Mighty Allah, Lord of the Great Throne, to grant you healing." If the death of that patient was to be delayed, he would be freed from that affliction.