Uthman bin 'Asim bin Husayn عثمان بن عاصم بن حصين أبو حصين · The Book of Zakah

"The Messenger of Allah said: 'Whoever asks when he has enough to make him independent of means will have lacerations on his face on the Day of Resurrection.' It was said: 'O Messenger of Allah, what would make him independent of means?' He said: 'Fifty Dirhams or its equivalent of gold."'