Charles Ellicott Commentary Genesis 2:4

"These are the generations of the heavens and of the earth when they were created, in the day that Jehovah God made earth and heaven." — Genesis 2:4 (ASV)

When they were created. —Hebrew, in, or upon, their creation.

In the day. —Viewed in its several stages, and with reference to the weekly rest, there were six days of creation, which are described here as one day, because they were merely divisions in one continuous act.

The Lord God. —Jehovah-Elohim. (See the Excursus at the end of this book.)