“Within the prison, shackled in iron chains, Vasudeva and Devaki gave birth to a male child year after year, and Kamsa, thinking each of the babies to be the incarnation of Vishnu, killed them one after another. He was particularly afraid of the eighth child, but after the visit of Narada, he came to the conclusion that any child might be Krishna. Therefore it was better to kill all the babies who took birth of Devaki and Vasudeva.” (Krishna, The Supreme Personality of Godhead, Vol 1, Ch 1)