ladder: This word occurs nowhere else in Scripture. The image may have reminded people at that time of a stairway or ramp on the front of a ziggurat (a large temple tower in ancient Mesopotamia). Such a structure was thought to connect heaven and earth (see study note on 11:4).
In this passage, God begins direct communication between heaven and earth to guide and protect Jacob, who carries his covenant (28:13–15; see Psalm 91:11–15).
Jesus later said that he himself is the way between heaven and earth (John 1:51).