Those who said the waiting period of an umm walad is one menstrual cycle

Sayyiduna Ibn Umar (may Allah be pleased with them both) said: The waiting period of an umm walad is one menstrual period.

Abu Qilabah (may Allah have mercy on him) said: If the master of an umm walad dies, her waiting period is one menstrual period.

Al-Hasan said: If the master of an umm walad dies, the waiting period of the slave woman (the umm walad) is one menstrual period.

Sayyiduna Zayd (may Allah be pleased with him) said: If the master of an umm walad dies, the waiting period of the slave woman (the umm walad) is one menstrual period.

Al-Dahhak (may Allah have mercy on him) said: If the master of an umm walad dies, the waiting period of the slave woman is one menstrual period.

Al-Sha'bi (may Allah have mercy on him) said: If the master of an umm walad dies, the waiting period of the umm walad is one menstrual period. If you make her waiting period three menstrual periods, then why do you not make her an heir of her master?!

Ata (may Allah have mercy on him) and Tawus (may Allah have mercy on him) said: The waiting period of an umm walad and of a concubine (a slave woman with whom her master has marital relations), when their master dies, is two months and five nights.

Yahya bin Sa'id (may Allah have mercy on him) said: Someone mentioned before al-Qasim (may Allah have mercy on him) that Abd al-Malik bin Marwan (may Allah have mercy on him) had separated some men from their wives who had been umm walads of their masters, but who had been married off after one or two menstrual periods. Abd al-Malik bin Marwan's (may Allah have mercy on him) order was that they observe a waiting period of four months and ten days. Hearing this, al-Qasim (may Allah have mercy on him) said: Subhan Allah! Allah Almighty says in the Qur'an: {And those of you who die and leave behind wives} [Al-Baqarah: 234]. So were these masters their husbands?