The ruling on one who promised a child a gift, but the child grew up and he did not give it to him

He also asks and says: When I was studying the Qur'an under one of the shaykhs in our country, I promised his son, who was five years old at the time, that I would bring him a tank. Then I traveled to the Kingdom and became occupied with work, and the time passed without me fulfilling this promise. The child I had promised grew up until he became a man. So, is it obligatory for me to fulfill this promise? And should I give him what I promised as stated in the promise, or something equivalent in value from goods that suit his age? Please advise us, may Allah reward you with good.
Answer: If you fulfill the promise, that is good and fine. Otherwise, the legal principles in such a case are that it is not obligatory for you, because its place is the time of childhood, and the custom in such matters is leniency among people. If what was easy for you to do during his childhood, then there is no blame on you, and praise be to Allah. But if you give him something, write to him, correspond with him, and give him something in return for this promise, that is good, from the perspective of the noble qualities of character. Yes.
The presenter: May Allah reward you with good.