‘They said therefore to him, “What then will you do for a sign that we may see and believe you? What work are you going to do? Our fathers ate the manna in the wilderness, as it is written ‘He gave them bread from Heaven to eat'.”
They at last caught on, or so they thought. Like Moses what Jesus was demanding was full obedience to Himself. And they recognised what a stupendous claim it was. Well, so be it. They were quite happy with that idea. In fact that is what they had had in mind. Let Him just prove Himself by continually giving them miraculous food and they would do whatever He wanted. (They conveniently forget how faithless their ancestors had been to the Moses who provided the bread from Heaven).
‘He gave them bread (food) from Heaven to eat'. See Nehemiah 9:15 where the manna, and possibly the quails, are described in this way as ‘bread from Heaven'. Consider also Psalms 78:24; Psalms 105:40.
They had already seen what may be thought of as almost His greatest sign. They had witnessed a miracle of supply. But instead of being filled with wonder and concentrating on Who this showed Jesus to be, and on what He had come to teach them they thought only of what was in it for them. They wanted not spiritual fulfilment but physical satisfaction. So they were basically saying ‘prove Who you are by giving us a sign and feeding us miraculously at this difficult time, just as Moses fed the people of Israel on their journey to the Promised Land' (John 6:30-31). Moses had given their ancestors bread from Heaven to eat. Let Jesus do the same. They overlooked the fact that their ancestors had taken it for granted and had continued in disobedience because they had not got their hearts right. Their minds were still on physical bread as a reward for obedience. But they had totally missed the point.
It is an interesting psychological study. The Pharisees saw Moses as supremely the Lawgiver, and that is what they taught the people. But the people saw Moses as the miraculous Provider. The laws were but a means to an end. In this the Pharisees were their superiors, for they primarily at least outwardly wanted to fulfil God's requirements. Yet in the end all lacked the one essential element. They were all out for what they could get, and ignored the need for personal response to God Himself. (Consider the Pharisee who ‘prayed to himself' (Luke 18:11)).