Does an oath of expiation become binding on one who swore not to go for Umrah while intending to go, and is the expiation to be given before or after going, and what is its monetary value?

You did well to conceal your righteous deed, but your oath not to go for 'Umrah was not well-considered; it would have sufficed to use circumlocution (Ma'areedh). If you swear to do something or not to do it, and then break your oath, expiation becomes obligatory upon you. It is permissible to offer expiation before breaking the oath or after it, but it is obligatory to hasten in offering it after breaking the oath. The expiation for an oath is feeding ten poor people, or clothing them, or freeing a slave. If one cannot find [any of these], then it is fasting for three days. It is not permissible to give the monetary value.