What is the ruling on an oath (Ila') conditioned upon acts of worship or permissible matters, such as vows (nadhr), fasting, prayer, or charity?

Primary text

When the oath of repudiation (Ila') is conditioned upon a vow, freeing a slave, fasting, prayer, charity, pilgrimage, or other acts of obedience or permissibility, the husband has the choice between fulfilling the condition or offering the expiation (kaffarah) for an oath. This is because such an oath is considered a vow made in anger and contention (Nadhr Lajaaj wa Ghadab).