Elijah went a day’s journey into the wilderness, and came and sat down under a solitary broom tree.  He asked that he might die: ‘It is enough; now, O Lord, take away my life, for I am no better than my ancestors.’  Then he lay down under the broom tree and fell asleep.  Suddenly an angel touched him and said to him, ‘Get up and eat.’  He looked, and there at his head was a cake baked on hot stones, and a jar of water.  He ate and drank, and lay down again.  The angel of the Lord came a second time, touched him, and said, ‘Get up and eat, otherwise the journey will be too much for you.’  He got up, and ate and drank; then he went in the strength of that food for forty days and forty nights to Horeb the mount of God.  At that place he came to a cave, and spent the night there.

This passage is seen as a sign of the Eucharist and is often paired with the Bread of Life discourse in John.  (John 6.22-71)

Elijah was weary, exhausted emotionally and physically from those who pursued him.  Why didn't the angel let him sleep?  He thought he needed physical rest when he actually needed sustenance from God.  Twice the angel woke him from sleep to tell him he needed the sustenance provided by God to sustain him instead of the rest he thought he needed.  (We can say "instead of" can't we, since the angel continued to interrupt his sleep instead of waiting for his repose to finish).

"Get up and eat, otherwise the journey will be too much for you."  This can be the theme of each and every day of the Christians life.  We think we need as much physical rest as the body demands.  In fact the Word tells us what we truly need for each day's tempestuous journey is to rise early from sleep and immerse ourselves in prayer with the Word.  For us these words might as well be "get up and pray, otherwise the day will be too much for you."  Expect the body to rebel, conditioned as it has been throughout its life to enjoy every comfort it desires.

When the disciples were concerned that Jesus had not been eating Jesus replied that "my food to do the will of him who sent me."  (John 4.34)  We must train and condition ourselves to view sustenance differently, to see it as daily prayer and obedience rather than food and sleep.