Jesus was heading to Galilee and, instead of taking the long way around Samaria the way any respectable first-century Jew would, he went right through the Land of the Half-Breeds and had a conversation with a woman that not only changed her life forever but the lives of almost everybody in town. (You can read the whole thing in John 4:1-42.)
In the midst of doing all this Samaritan life-changing, Jesus also fits in a learning opportunity for his disciples. They had gone into town to buy some food, but when they returned to the well on the outskirts of town, they were surprised that Jesus wasn't all that hungry.
Verses 33 & 34: Then his disciples said to each other, "Could someone have brought him food?" "My food," said Jesus, "is to do the will of him who sent me and to finish his work." (NIV)
Truth is...spiritual nourishment isn't all about studying the Bible and listening to sermons and "getting fed." A person also grows and learns and is fulfilled by "doing unto others."