SB 10.4.4

tam āha bhrātaraṁ devī
 kṛpaṇā karuṇaṁ satī
snuṣeyaṁ tava kalyāṇa
 striyaṁ mā hantum arhasi
Word for word: 
tam — unto Kaṁsa; āha — said; bhrātaram — her brother; devī — mother Devakī; kṛpaṇā — helplessly; karuṇam — piteously; satī — the chaste lady; snuṣā iyam tava — this child will be your daughter-in-law, the wife of your future son; kalyāṇa — O all-auspicious one; striyam — a woman; — not; hantum — to kill; arhasi — you deserve.
Translation: 
Devakī helplessly, piteously appealed to Kaṁsa: 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: 

Kaṁsa had previously excused Devakī because he thought that a woman should not be killed, especially when pregnant. But now, by the influence of māyā, he was prepared to kill a woman — not only a woman, but a small, helpless newborn child. Devakī 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 Devakī, on the contrary, although safe because she had already given birth to her own son, Kṛṣṇa, was anxious to save the daughter of someone else. This was natural for her.