Is Zakat obligatory on a sum of money designated to help needy relatives, which is collected and distributed to them according to need, and which reached 40,000 Riyals after four years of collection?

The money allocated for the needy, if it does not reach them, then its zakat is due from the donor, because the gift is not complete. However, after it is received by the needy, zakat becomes obligatory on whoever's share reaches the nisab and a full year has passed while it does not fall below it. The nisab for cash is the equivalent of 85 grams of gold or 595 grams of silver, and its zakat is a quarter of a tenth (2.5%).