What is the ruling on the zakat for a sum of seventy thousand dirhams that was spent before its obligatory zakat was paid, due to its owner's ignorance of its obligation, and what is the amount of zakat due on this sum?

Zakat must be paid on the aforementioned amount if a full year has passed on it, provided it reaches the nisab (minimum threshold) by itself or when combined with other money or trade goods. If some of it is spent during the year, then zakat is due on the remaining amount at the end of the year, provided it still meets the nisab, and it did not fall below the nisab throughout the year. If the amount is spent before the zakat due date without the intention to evade, then there is no zakat on it and no sin. The nisab for banknotes and the payable amount are detailed in Fatwa No. 31079. If zakat becomes due on seventy thousand, the zakat amount is one thousand seven hundred and fifty dirhams (a quarter of a tenth).