John 6:27-31

Labour not for the meat which perisheth, but for that meat which endureth unto everlasting life, which the Son of man shall give unto you: for him hath God the Father sealed.

Then said they unto him, What shall we do, that we might work the works of God?

Jesus answered and said unto them, This is the work of God, that ye believe on him whom he hath sent.

They said therefore unto him, What sign shewest thou then, that we may see, and believe thee? what dost thou work?

Our fathers did eat manna in the desert; as it is written, He gave them bread from heaven to eat.