ما هي الكفارة الواجبة على من نذر ألا يكلم شخصًا ثم كلمه؟

It is forbidden to abandon a Muslim merely for personal gratification unless the motive is religious. If one vows to abandon a Muslim for eternity, their vow is unlawful. Scholars differ on this matter: some say the vow is binding and requires expiation (kaffarah) for breaking an oath, while others say the vow is not binding and does not require expiation. Adopting the first opinion is more cautious. The expiation for breaking an oath is: feeding ten poor persons, or clothing them, or freeing a slave. If one cannot find any of these, then fasting for three days.