Jesus told his disciples that what sustained him was doing his Father’s will, which meant convincing non-Jewish people to believe in him.

John 4:31-38

31 Meanwhile, we disciples were urging him, “Teacher, eat some of the food we brought!” 32 But he said to us, “I have food to eat that you do not know anything about!” 33 So we started saying to each other, “◄Surely no one has brought him any food when we were not here!/Has anyone brought him any food when we were not here?► [RHQ]” 34 Jesus said to us, “Doing what my Father who sent me wants me to do and finishing the work he gave me to do is ◄what sustains me/like my food► [MET]. 35 At this time of the year you are saying (OR, your ancestors used to say), ‘There are four months left before we harvest the crops.’ But I say to you, look carefully at the non-Jewish people around here. God says, ‘They are ready to accept my message [MET], like crops in fields that are ready for people to harvest. 36 If you help them to accept my message, I will reward you [MET], as an owner of a field pays those who harvest the crops. Because of your work, people will gain eternal life.’ I have been telling people God’s message. That is like [MET] a man who plants seeds. You will help people to accept my message. That will be like [MET] harvesting crops. When that happens, both you and I will rejoice. 37 As a result, this saying will become true: One person plants seeds, but others harvest the crops. 38 I am sending you to enable people to accept my message, but you will not be the first ones who tell them God’s message. Others previously worked hard to tell people God’s message, and now you will be harvesting the results of their work.”