kamsah papa-matih sakhyam
devakya astamo garbho
na stri bhavitum arhati
iti sañcintayañ chrutva
api hanta gatasankas
tarhi tan no ’nayo bhavet
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Kamsa is both a great diplomat and a very sinful man. Therefore, having heard from Yoga-maya, the daughter of Devaki, that the child who will kill him has already been born somewhere else, having heard that the eighth pregnancy of Devaki could not bring forth a female child, and having understood your friendship with Vasudeva, Kamsa, upon hearing that the purificatory process has been performed by me, the priest of the Yadu dynasty, may certainly consider all these points and suspect that Krsna is the son of Devaki and Vasudeva. Then he might take steps to kill Krsna. That would be a catastrophe.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Kamsa knew very well that Yoga-maya was, after all, the maidservant of Krsna and Visnu and that although Yoga-maya had appeared as the daughter of Devaki, she might have been forbidden to disclose this fact. Actually this was what had happened. Garga Muni argued very soberly that his taking part in performing the reformatory process for Krsna would give rise to many doubts, so that Kamsa might take very severe steps to kill the child. Kamsa had already sent many demons to attempt to kill this child, but none of them had survived. If Garga Muni were to perform the purificatory process, Kamsa’s suspicions would be fully confirmed, and he would take very severe steps. Garga Muni gave this warning to Nanda Maharaja.