Dua #1052•At-Tirmidhi, Abu Dawud. See also Al-Albani, Sahih At-Tirmidhi 2/210 and Sahihul-Jami' As-Saghir 5/180.

When visiting the sick

Hisnul Muslim
#1052

أَسْـأَلُ اللهَ العَـظيـم رَبَّ العَـرْشِ العَـظيـم أَنْ يَشْفـيك (سبع مرات)

Transliteration

As'alullāha ‘l-`Aẓīma Rabba ‘l-`Arshil-`Aẓīmi an yashfiyak.

Translation

I ask Almighty Allah, Lord of the Magnificent Throne, to make you well. (Recite seven times in Arabic .)