عَنْ عَلِيٍّ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ: ((قَدْ عَفَوْتُ لَكُمْ عَنِ الْخَيْلِ وَالرَّقِيقِ فَهَاتُوا صَدَقَةَ الرِّقَاقِ مِنْ كُلِّ أَرْبَعِينَ دِرْهَمًا دِرْهَمًا وَلَيْسَ فِي تِسْعِينَ وَمِائَةٍ شَيْءٌ، فَإِذَا بَلَغَتْ مِائَتَيْنِ فَفِيهَا خَمْسَةُ دَرَاهِمَ))
It is narrated from Sayyiduna Ali (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: I have exempted you from zakat on horses and slaves, but you must pay one dirham as zakat for every forty dirhams of silver. If the silver is one hundred and ninety dirhams, then there is no zakat on it; when it reaches two hundred dirhams, then five dirhams are due as zakat.