SB 9.9.31
tasya sadhor apapasya
bhrunasya brahma-vadinah
katham vadham yatha babhror
manyate san-mato bhavan
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
You are well known and worshiped in learned circles. How dare you kill this brahmana, who is a saintly, sinless person, well versed in Vedic knowledge? Killing him would be like destroying the embryo within the womb or killing a cow.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
As stated in the Amara-kosa dictionary, bhruno ’rbhake bala-garbhe: the word bhruna refers either to the cow or to the living entity in embryo. According to Vedic culture, destroying the undeveloped embryo of the soul in the womb is as sinful as killing a cow or a brahmana. In the embryo, the living entity is present in an undeveloped stage. The modern scientific theory that life is a combination of chemicals is nonsense; scientists cannot manufacture living beings, even like those born from eggs. The idea that scientists can develop a chemical situation resembling that of an egg and bring life from it is nonsensical. Their theory that a chemical combination can have life may be accepted, but these rascals cannot create such a combination. This verse refers to bhrunasya vadham — the killing of a bhruna or destruction of the embryo. Here is a challenge from the Vedic literature. The crude, atheistic understanding that the living entity is a combination of matter belongs to the grossest ignorance.