The prohibition is short and its reason is shorter. Bahá’u’lláh forbids the buying and selling of human beings, men or women, and then gives the ground: one who is himself a servant of God has no standing to buy another of God’s servants. The ban rests not on sentiment about kind masters but on a fact about everyone, that each person already belongs to God and so cannot be anyone else’s property. That single thought has a long reach, because the same reasoning that forbids the auction block also unsettles every quieter way one person turns another into an instrument. The prayer of emancipation and the account of freedom within Bahá’u’lláh’s household give that principle a practical form, while the criticism of monuments built by enslaved people tests what a society calls greatness. Seneca, writing to a slaveholder, pleads that the enslaved breathe the same air, were born as he was and will die as he will, and asks for kindness and companionship; yet he stops at humane treatment inside the institution, where Bahá’u’lláh forbids the transaction itself [1]. The distance between those two positions is the whole question. It leads on to the oneness of humanity, and to a unity that is not a hope laid over inequality but a standing to be recognised in every servant of God.
It is forbidden you to trade in slaves, be they men or women. It is not for him who is himself a servant to buy another of God's servants, and this hath been prohibited in His Holy Tablet.
(Bahá’u’lláh, Kitab-i-Aqdas (The Most Holy Book), 1290-05-15 [1873-Jul-11] -- BH00001)
02
Glorified art Thou, O Lord my God! Behold how one slave hath stood at the door of another, seeking from him his freedom, and this despite the fact that his owner is himself but Thy thrall and Thy servant, and is evanescent before the revelations of Thy supreme Lordship. I testify at this moment, as I stand before Thee, to that whereunto Thou didst testify to Thyself, by Thyself, that verily Thou art God and there is none other God but Thee. From everlasting Thou hast inhabited the loftiest heights of power, might, and majesty, and wilt to everlasting continue to abide in the sublimity of Thy glory, awe, and beauty.
All kings are as vassals before the gate of Thy grace, the rich are but destitute at the shore of Thy sacred dominion, and all great ones are but feeble creatures within the court of Thy glorious bounty. How, then, can this thrall claim for himself ownership of any other human being? Nay, his very existence before the court of Thy might is a sin with which no other sin in Thy kingdom can compare. Glorified, immeasurably glorified, art Thou beyond every description and praise.
O my God! Since he hath asked this servant for his freedom, I call Thee to witness at this moment that I verily have set him free in Thy path, liberated him in Thy name, and lifted from his neck the shackles of servitude, that he may serve Thee in the daytime and in the night-season, whilst I pray that Thou mayest never free mine own neck from the chain of Thy servitude. This verily is my highest hope and supreme aspiration, and to this Thou Thyself art a mighty witness.
Toward the end of his talk he related the story of Esfandeyar [Isfandiyar], the colored attendant of Baha'u'llah. "In his palace my grandfather" he commenced "had many colored maids and servants. When the Blessed Perfection became the head of the family he liberated all of them and gave them his permission to leave or stay, but if they desired to remain it will be of course in a different manner. However, all of them revelling in their new found freedom preferred to leave except Esfandeyar. He remained in the household and continued to serve us with proverbial faithfulness and chastity.
(‘Abdu’l-Bahá, Words spoken on 1913-Oct-25 in Ramleh -- ABU2597)
04
Late in the afternoon I happened along just as 'Abdul Baha and Dr. Fareed were starting out for a drive, so I accompanied them. We drove past the White House and through the grounds around the Washington Monument. Calling 'Abdul Baha's attention to the monument, I remarked that it was higher than the Great Pyramid, whereupon 'Abdul Baha said that to many people the great Pyramid was the most to be admired structure in Egypt, but to him it had always produced an unpleasing impression, for it recalled to his mind the intense suffering of the thousands of slaves and captives who were under the oppressor who built the pyramid for his tomb.
(‘Abdu’l-Bahá, Words to Mr. Remey, spoken near the Washington Monument on 1912-Apr-20 -- ABU2923)