Muhammad bin 'Uthman bin Abi Safwan محمد بن عثمان بن أبي صفوان · The Book of Adornment

'Ali said: "The Messenger of Allah said to me: 'O 'Ali, ask Allah for guidance and steadfastness,' and he forbade me from placing a ring on this one and this one' - and he pointed to his forefinger and middle finger.