Answer:
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.