Commentaries:
God is assured that He has first place in the heart of his servant Abraham. Again, notice the tenderness in the words. He calls Isaac "your son, your only son," thinking no doubt of His own relationship with His Father.
Mike Ford
Abraham's One God
God laid His hands on Egypt in divine judgment by sending plagues. When trying a blasphemer, each witness placed his hands upon the guilty person to signify his acceptance of the verdict. Conversely, when a victim was spared death—as when God commanded Abraham not to sacrifice Isaac or when He allowed the leaders of Israel to see Him without dying—mercy is described as hands not being laid on the spared victim.
Martin G. Collins
Basic Doctrines: The Laying On of Hands