R. Ishmael questioned R. 'Aqiva, who was interpreting the words akh ("but") and raq ("only") as indicating exclusions, with et (either the sign of a definite accusative or the preposition "with") and gam ("also") as indicating inclusions. R. Ishmael said to him: "In the beginning God created heaven and earth" is not written here but ET THE HEAVEN AND ET THE EARTH. The use of ET is simply a clarification of Scripture. R. 'Aqiva said to him: It is written (in Deut. 32:47): FOR IT (the Torah) IS NO EMPTY THING FOR YOU. If "heaven and earth" had been stated (in Gen. 1:1), we should have said: They are two deities. But ET THE HEAVEN AND ET THE EARTH means those two creations and what was created along with them.
Rabbi Akiva's Argument Over Two Tiny Hebrew Particles
Midrash Tanchuma Buber, Bereshit 8:1