It is narrated from Qasim bin Muhammad that he used to say: When the master of an umm walad slave-woman dies, her waiting period (‘iddah) is one menstrual cycle.
Imam Malik, may Allah have mercy on him, said: According to us, this is the ruling.
Hadith Referenceموطا امام مالك رواية يحييٰ / كتاب الطلاق / 1234