“Let there be light” is an English translation of the Hebrew יְהִי אוֹר (yehi ‘or) found in Genesis 1:3 of the Torah, the first part of the Hebrew Bible. In Old Testament translations of the phrase, translations include the Greek phrase γενηθήτω φῶς (genēthḗtō phôs) and the Latin phrases fiat lux and lux sit.
The phrase comes from the third verse of the Book of Genesis. In the King James Bible, it reads:
(1) In the beginning God created the heaven and the earth.
(2) And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
(3) And God said, Let there be light: and there was light.
(4) And God saw the light, and it was good; and God divided the light from the darkness.