The Messenger of Allah ﷺ said: ʿI have relieved you of zakah on horses and slaves, but bring one quarter of one tenth, for every forty dirhams, one dirham.ʿ
قَالَ رَسُولُ اللهِ ﷺ قَدْ عَفَوْتُ لَكُمْ عَنْ صَدَقَةِ الْخَيْلِ وَالرَّقِيقِ وَلَكِنْ هَاتُوا رُبُعَ الْعُشُورِ مِنْ كُلِّ أَرْبَعِينَ دِرْهَمًا دِرْهَمًا