tam aha bhrataram devi
krpana karunam sati
snuseyam tava kalyana
striyam ma hantum arhasi
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Devaki helplessly, piteously appealed to Kamsa: My dear brother, all good fortune unto you. Don’t kill this girl. She will be your daughter-in-law. Indeed, it is unworthy of you to kill a woman.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Kamsa had previously excused Devaki because he thought that a woman should not be killed, especially when pregnant. But now, by the influence of maya, he was prepared to kill a woman — not only a woman, but a small, helpless newborn child. Devaki wanted to save her brother from this terrible, sinful act. Therefore she told him, “Don’t be so atrocious as to kill a female child. Let there be all good fortune for you.” Demons can do anything for their personal benefit, not considering what is pious or vicious. But Devaki, on the contrary, although safe because she had already given birth to her own son, Krsna, was anxious to save the daughter of someone else. This was natural for her.