What is the rhetorical touch in the difference in wording between "are killed" (يقتلون) in the first verse and "are slaughtered" (يذبحون) in the second verse, while all other words are in agreement?

Pharaoh exacted two retributions upon the Children of Israel: The first was for their alliance with the Hyksos, during which he killed them and burned their homes. As for the second retribution, which was the slaughter of their sons, it was due to a vision Pharaoh had, which the priests interpreted as a newborn from the Children of Israel being the cause of the demise of his kingdom. So, he ordered the slaughter of every male infant among them. When Pharaoh's people feared the extinction of the Children of Israel, he made the slaughter every other year. Thus, Aaron, who was born in a year without slaughter, survived, while Moses was born in a year of slaughter. The reason for the slaughter was to ensure the death of the newborn and prevent their survival.