Oh, how dreadful that my mother had to undergo great pain. For ten months she guarded and carried me. After my birth, she took care that I should always be in dry place instead of damp, and cleaned my excretions; she gave me milk and fed me so that I have grown up. For all of this, I must repay her what I owe her, see to her feelings, be obedient to her and serve her. What writer wants to write about mother's love?

express a mother's unconditional love.

Explanation:

These lines are found in the Buddhist book of "Nirvana Sutra" and is believed to have said by Buddha himself to express a mother's unconditional love. It expresses the essence of filial piety, the act of being good and obedient towards one's own parents.

Buddha remarks how hard and dreadful experience that his mother had to undergo just to give birth to him and raise him up. He says that a mother's love for her child is unceasing and unconditional. Therefore, it is one's duty to honour and to be obedient to one's own mother in return for all she had gone through for him/her.

heritage? culture? religion? gene? trait?

they are direct opposites. they can both be corrupted. they are inseparable.