There was once a moment — so the rabbis taught — when the universe would not stop growing. Midrash Tanchuma Buber, Bereshit 11:3 preserves a cosmology that would sound at home in modern physics.
R. Aha's teaching
R. Aha described the moment of creation this way: "When the Holy One spoke to the heavens that they should be created, they went on expanding. If He had not said: Enough, they would have gone on expanding out until the dead arose."
The Hebrew word for "enough" is dai — דַּי. R. Aha read this into the divine name Shaddai (שַׁדַּי), one of the names of God, as meaning "the one who said dai" — the one who set the limit. The midrashic tradition developed this wordplay into a whole theology. God's role in creation was not only to start the process but to stop it.
A universe without a limit
Picture the image the midrash is drawing. God speaks, and the heavens begin to unfold. But they keep unfolding. The cosmic fabric continues to stretch, outward and outward. Without an upper boundary, the expansion would have gone on "until the dead arose" — until the messianic future folded back into the present moment. Space itself would have overflowed time.
Only the divine word dai imposed a limit. Enough heaven. Enough distance. Enough stretching.
The ethics of "enough"
The rabbis drew a moral lesson from this physical observation. The universe was created with the principle of dai built into its structure. Things have natural limits, and holiness often lies in recognizing them.
This echoes across Jewish practice. Shabbat is dai for work. The sabbatical year is dai for agriculture. The laws of charity require giving, but the <a href='/categories/midrash-rabbah.html'>rabbinic code</a> also caps it — you should not impoverish yourself. Even in Passover seder liturgy, the song Dayenu — "it would have been enough" — celebrates the virtue of sufficiency.
The cosmological parallel
Modern cosmology postulates that the early universe expanded rapidly in an event called inflation, which then slowed dramatically. Whatever one makes of the coincidence, R. Aha was working with an ancient intuition — that unchecked expansion is its own kind of death, and that the world requires a word of limitation to become a home.
Without dai, the heavens would be infinite and uninhabited. With dai, they are finite and full of stars.
The takeaway: the universe was created by the word "let there be" and preserved by the word "enough." Both are divine. And learning when to say which one is part of what it means to live inside creation.