Mark 14:40
ESV
And again he came and found them sleeping, for their eyes were very heavy, and they did not know what to answer him.
NIV
When he came back, he again found them sleeping, because their eyes were heavy. They did not know what to say to him.
NASB
And again He came and found them sleeping, for their eyes were heavy; and they did not know what to say in reply to Him.
CSB
And again he came and found them sleeping, because they could not keep their eyes open. They did not know what to say to him.
NLT
When he returned to them again, he found them sleeping, for they couldn’t keep their eyes open. And they didn’t know what to say.
KJV
And when he returned, he found them asleep again, (for their eyes were heavy,) neither wist they what to answer him.
NKJV
And when He returned, He found them asleep again, for their eyes were heavy; and they did not know what to answer Him.
What does Mark 14:40 mean?
Jesus is praying in the garden of Gethsemane the night before the crucifixion. Twice He's asked Peter, James, and John to stay up and watch and pray (Mark 14:34, 38). He doesn't ask them to pray for Him; He knows His future is decided even as He prays that God will change it (Mark 14:35–36). He wants them to pray that they can resist temptation in the time to come (Mark 14:38).One of Satan's most effective strategies is to make our "eyes heavy" to his devastating work. While it's paranoid to think there is a demon behind every bush, it's also foolish to ignore the possibility that we will be confronted with spiritual warfare. Paul calls us to not be "ignorant of [Satan's] designs" (2 Corinthians 2:11). Peter says that Satan "prowls" and "seeks someone to devour" (1 Peter 5:8), showing that Satan is strategic in his attacks. It's certainly easier to attack someone who doesn't believe you're a threat. And, of course, when they're tired from a long day and full of food, as the disciples are.
Prayer to God makes a strong defense against the enemy. After the transfiguration, Jesus comes down the mountain with Peter, James, and John to find the rest of the disciples arguing with the scribes because the disciples could not free a boy from a dangerous demon (Mark 9:14–18). Jesus expels the demon, and the disciples ask why they were powerless. Jesus says, "This kind cannot be driven out by anything but prayer" (Mark 9:29).
Prayer isn't just to tell God what we want or ask for help when we get what we don't want. It's also designed to prepare us for spiritual battle. God is willing to equip us to fight temptation and the effects of the enemy. We should take advantage of His offer.
Mark 14:32–42 contains Jesus' wait in the garden of Gethsemane. This describes Jesus' example and the disciples' catastrophic failure to follow the general theme of Jesus' admonition in Mark 13:32–37. Jesus watches how God moves and prays for His part in it. The disciples sleep. Three times, their Master finds them unconscious, both physically and spiritually (Mark 13:35–36). They do not take the time, as Jesus does, to prepare for the hardships in front of them. They so expect Jesus' victory over the Roman occupiers they don't prepare for His spiritual war on the cross. This story is also in Matthew 26:36–46 and Luke 22:39–46.
Jesus is anointed in a symbolic anticipation of His death. Judas decides to secretly cooperate with local religious leaders to arrest Jesus in secret. During the Passover meal, Jesus predicts His betrayal by Judas, and Peter's denial. He also institutes the Lord's Supper, also known as communion. After praying on the Mount of Olives, Jesus is captured when Judas identifies Him to a hostile mob sent by Jewish authorities. He endures a corrupt, prejudiced trial, ending in a conviction for blasphemy. Peter, fearing for his life, lies about knowing Jesus, before remembering Jesus' prediction and breaking down in sobs.