The Cup That Jesus Feared

The night He was betrayed the Lord Jesus took His disciples with Him to the Garden of Gethsemane and said, "My soul is exceeding sorrowful, even unto death: tarry ye here, and watch with me." He then went a little further, to where He fell three times on His face and prayed to His Father, "O my Father, if it be possible, let this cup pass from me." WHAT WAS IN THAT CUP -- that Jesus feared?