#He dreamed

"Jacob had a dream"

#set up on the earth

"with the bottom of it touching the ground"

#reached to heaven

This refers to the place where God lives.

#Behold

The word "behold" here alerts us to pay attention to the surprising information that follows.

#Yahweh stood above it

Possible meanings are 1) "Yahweh was standing at the top of the stairway" or 2) "Yahweh was standing next to Jacob"

#Abraham your father

Here "father" means "ancestor." AT: "Abraham your ancestor" or "Abraham your forefather"