Genesis 1:21

התנינים THE HUGE CREATURES — the large fishes that are in the sea; and according to the statement of the Agada (Bava Batra 74b) it means here the Leviathan and its consort which He created male and female. He, however, killed the female and preserved it in salt for the benefit of the righteous in the time to come, for had they been permitted to be fruitful and to multiply the world could not have endured because of them. נפש חיה — that have vitality.

וַיִּבְרָ֣א אֱלֹהִ֔ים אֶת־הַתַּנִּינִ֖ם הַגְּדֹלִ֑ים וְאֵ֣ת כׇּל־נֶ֣פֶשׁ הַֽחַיָּ֣ה ׀ הָֽרֹמֶ֡שֶׂת אֲשֶׁר֩ שָׁרְצ֨וּ הַמַּ֜יִם לְמִֽינֵהֶ֗ם וְאֵ֨ת כׇּל־ע֤וֹף כָּנָף֙ לְמִינֵ֔הוּ וַיַּ֥רְא אֱלֹהִ֖ים כִּי־טֽוֹב׃

And God created the great crocodiles, and every living creature that moves, which the waters brought forth abundantly, after their kind, and every winged bird after its kind: and God saw that it was good.