Does the amount that the affluent father was supposed to spend on his needy, dependent son become a debt to be deducted from the inheritance after the father's death?

The father is obligated to provide for his minor children. As for adult children, if they are poor (according to the Hanbali school of thought), even if they are able to earn a living, the father is obligated to provide for them. However, the majority of scholars do not obligate the father to provide for an adult son who is able to earn a living. The father is not obligated to provide support if the son's stay in a foreign country doubles the expenditure. The children's maintenance (nafaqah) lapses with the passage of time and does not become a debt owed by the father or mother, unlike the wife's maintenance, which does not lapse over time.