Musannaf Ibn Abi Shaybah 10146 — Dinars: what is taken from them

Ata said: Zakah is not due on wealth until it reaches twenty dinars. When it reaches twenty dinars, half a dinar of zakah is due on it; and on every four dinars by which it exceeds that, one dirham keeps being due, until it reaches forty; and on every forty, one dinar is due; and on twenty-four dinars, half a dinar and one dirham are due.