Is zakat obligatory on the money of minor orphans deposited in an Islamic bank and saved to meet their basic needs, given the insufficiency of other sources of income?

Zakat is obligatory on saved money if it reaches the threshold (nisab). It is a quarter of a tenth (2.5%) to be paid every Hijri year, based on the statement of Sheikh Ibn Uthaymeen that it is obligatory on money saved for marriage, buying a house, and similar purposes. Zakat increases wealth and blesses it.