Is the Udhiyah an obligation or not, and is it permissible to be hard on oneself to perform it, and is giving money to a needy son more preferable than the Udhiyah?

The Udhiyah (definition) (sacrifice) is a confirmed Sunnah (definition) according to the majority of scholars. It is permissible to save its cost or borrow money for it, for one who expects to be able to repay, provided that this does not lead to neglecting essential expenditures. If there is an essential expenditure, such as a son's maintenance of his mother, then this expenditure takes precedence over the Udhiyah. However, if the expenditure is not essential, then the Udhiyah is better than donating its cost as charity.