Is it obligatory for male and female servants (of Zoroastrians) who have faith in the Good Religion (Zoroastrianism) to tie the sacred belt (kusti)? This was one of the questions raised by early Parsis in India to the clergy in Iran. Only if they have faith in the religion, was the answer from the Iranian priests. PhD candidate Kiyan Foroutan (pictured) conveyed this while speaking at The K. R. Cama Oriental Institute (KRCOI) on January 21, 2019 on "The question of domestic slaves in Persian Rivayats: Their Legal-ritual status in early modern Zoroastrianism.” "And when they become smart and knowledgeable in religion and steadfast, they 
(the masters) should perform bareshnum (nine-day purification ritual) for them, and it is allowable and obligatory to eat something out of their hand,” the communication continued. Foroutan is pursuing a doctoral program at the Centre for the Study of Religion at Leiden University, The Netherlands.
The Rivayats are a series of correspondence exchanged between Iranian and Parsi Zoroastrians from the late 15th century to the late 18th century and encapsulate the guidance proffered by Iranian Zoroastrians to their Indian brethren on customs and manners as the Iranians were considered an authority on the subject. Parsiana had reprinted excerpts from Ervad Bamanji Dhabar’s 1932 publication The Persian Rivayats of Hormazyar Framarz and others — Their version with introduction and notes (see "The Persian Rivayats,” Parsiana, July 2003). Dhabar’s volume was reprinted in 1999 by KRCOI.
Receiving baj (which Foroutan translated as "sanctified food”) from the hands of a slave was permissible for a priest only if the slave was liberated, and wore a sudreh-kusti, according to another Rivayat. Yet another vexatious question asked by Parsis to the Iranian clergy was whether a servant who was taught the Avesta, invested with a sudreh-kusti, and from whose hands food was taken, could be consigned to a dakhma. The Iranian priests said no, according to Foroutan, admitting that in reality conversions were few and far between. Many questions asked in the Rivayats were hypothetical in nature and their answers reflected much older wisdom on the subjects, said the research student.
Slave owning (keeping of servants) was not the prerogative of rich Parsis only, said Foroutan. Servant-slaves, mostly from coastal East Africa were traditionally kept in Iranian households too. There also may have been Zoroastrian slaves in Parsi homes, he said. "They should be treated as Zoroastrian children are,” was the directive from the Iranian priests.
Founder of Zoroastrian Studies and former Bombay Parsi Punchayet trustee Khojeste Mistree who was present in the audience stated that there exists no written evidence that slaves, in the strict sense of the term, were owned by Parsi families, or that bareshnum was given to non-Zoroastrian women.
Of interest to readers may be questions raised by the Indians and mentioned in Dhabar’s translation. "Can a grave digger, a corpse-bearer and a darvand (one of foreign faith) become behdins?” The response from the Iranian priests: "If they observe the rules of the religion steadfastly and (keep) connection with the religion, and if no harm comes to the behdin (thereby), it is proper and allowable.”
Zoroastrian slave keepers were allowed to marry their female slaves after proper purification rituals. "A young (female) prisoner of war, bought (of another)... should be fed for three nights in a public place and then her head should be washed with the bareshnum and then she should be married.” A longer "feeding” period is prescribed if the slave were in her menses.