Zakat on jewellery unpaid for seventeen years: is the zakat of past years binding?

Question

For about twenty years I have had forty tolas (a unit of weight, ≈ 11.66 g) of gold and a good deal of silver — several seers (a unit of weight, ≈ 0.93 kg). Since I have this much gold and silver, zakat on it has been wajib from that very time. But for seventeen years [I] understood that zakat is given on the jewellery that is used, and not on the rest. Now I have learned that zakat must be given on all the jewellery, so for three years I have been giving zakat on all of it.

Answer

Silver and gold — whether in the form of jewellery or in any other form, and jewellery — whether in use or not, in every case zakat is binding (lazim). From the time [the property] comes into ownership and a full year passes over it, giving zakat every year is necessary, whether one knows that zakat is fard or not. Therefore the zakat of the past seventeen years is binding.

Source: Fatawa Mahmudiyya

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