Therefore they said to Him, "What sign will You perform then, that we may see it and believe You? What work will You do?
John 6:30
Surrounding context
6:29 Jesus answered and said to them, "This is the work of God, that you believe in Him whom He sent."
6:30 Therefore they said to Him, "What sign will You perform then, that we may see it and believe You? What work will You do?
6:31 Our fathers ate the manna in the desert; as it is written, "He gave them bread from heaven to eat."'