Rashi on Genesis 5:24/רש"י על בראשית ה׳:כ״ד

1ויתהלך חנוך AND ENOCH WALKED [WITH GOD] — He was a righteous man, but his mind was easily induced) to turn from his righteous ways and to become wicked. The Holy One, blessed be He, therefore took him away quickly and made him die before his full time. This is why Scripture uses a different expression when referring to his death by writing ואיננו “and he was not”, meaning, he was not in the world to complete the number of his years.

2כי לקח אותו FOR GOD TOOK HIM — before his time; a similar meaning of לקח “to take” we find in (Ezekiel 24:16), “I take away from thee the desire of thine eyes [by a plague]”.