If there is a conflict between his father’s instructions and doing something he vowed (nadhr) to do, which should take precedence?

Swearing by acts of worship is haraam but there is no expiation for it

She swore a false oath; how can she expiate that?

Is it mustahabb to observe fasts in expiation for breaking an oath as the six days of Shawwaal?

He vowed to do Hajj every year but his boss at work will not let him do that

She vowed that if the arguments with her husband ceased, she would fast on Thursdays forever

He vowed to take his mother for ‘Umrah on the day of Eid; can he take her for ‘umrah in Ramadan?

When there is a conflict between fulfilling an oath and honouring one’s parents

He pledged to give some money in charity and he does not have that money now

She vowed to sacrifice a sheep on behalf of her mother; can she offer the charity in the form of money instead?