Answered by Shaykh Abdul-Rahim Reasat
For example, a promise was made to donate or give away a specific amount of money many years back, say in 1983. This did not happen, and fast forwarding to the present day, a decision has been made to make that payment and fulfill the promise. Does one need to calculate how much the original sum is now worth in today’s money, or will the initial sum suffice?
I pray you are well. It would be sufficient to give the amount you initially promised to donate. You don’t need to increase the amount.
One thing you’ll notice about spending in the way of Allah is that whatever you spend tends to come back to you. Sometimes, it’s as money, and at other times, as something else. But, no matter what, “every single thing you spend, He will replace it.” [Quran, 34:39]
May Allah grant you the best of both worlds.
[Shaykh] Abdul-Rahim Reasat
Checked and Approved by Shaykh Faraz Rabbani