Imam Malik, may Allah have mercy on him, said: The zakat al-fitr of the slaves of one’s slave, and of one’s servant, and of the slave of one’s wife is not obligatory upon a person, except for the one among them who serves him, then its zakat will be obligatory. Imam Malik, may Allah have mercy on him, said: The zakat al-fitr is not obligatory on behalf of slaves who are disbelievers until they become Muslim, whether they are for trade or not.
Hadith Referenceموطا امام مالك رواية يحييٰ / كتاب الزكاة / 703