The Dhauli Edict has:

If a man is subject to slavery and ill-treatment, from this
moment he shall be delivered by the king from this and other
captivity. Many men in this country suffer in captivity,
therefore the stupa containing the commands of the king has
been a great want.

Is it reasonable to suppose that a people possessing so much wisdom, mercy, and purity two centuries before Christ was born could need to borrow from the Christian ethics?

Mr. Lillie says of King Asoka:

He antedates Wilberforce in the matter of slavery. He antedates
Howard in his humanity towards prisoners. He antedates Tolstoy
in his desire to turn the sword into a pruning-hook. He antedates
Rousseau, St. Martin, Fichte in their wish to make interior
religion the all in all.

King Asoka abolished slavery, denounced war, taught spiritual religion and purity of life, founded hospitals, forbade blood sacrifices, and inculcated religious toleration, two centuries before the birth of Christ.

Centuries before King Asoka the Buddhists sent out missionaries all over the world.

Which religion was the borrower from the other—Buddhism or Christianity?

Two centuries before Christ, King Asoka had cut upon the rocks these words:

I pray with every variety of prayer for those who differ with
me in creed, that they, following after my example, may with
me attain unto eternal salvation. And whoso doeth this is
blessed of the inhabitants of this world; and in the next
world endless moral merit resulteth from such religious charity
Edict XI.