Jesus said to them, “My food is to do the will of Him who sent Me, and to finish His work.
John 4:34, NKJV
The disciples came back from the store and found themselves in the middle of a comedy of errors. When Jesus had spoken with the Samaritan Woman, she had not understood why a Jewish man would talk with her. She could not grasp that Living Water was a metaphor not intended literally. She did not comprehend that Jesus was greater than Jacob.
Just like the Samaritan Woman was totally clueless concerning the beverage, the disciples were completely dumbfounded regarding the entree. When they implored Jesus to eat, He mentioned food they knew nothing about. Next it was their turn to take Jesus literally and assume He had already eaten. Jesus explained His spiritual appetite was to obey the Father and share the message of the Kingdom. Lost people thirst for the gospel. Christians must hunger to proclaim it.