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

(6) The spiritual virtue of Christ is condemned by those that desire earthly miracles.

People's New Testament

6:30 What sign shewest thou then, that we may see, and believe thee? He had pointed to himself as the object of faith, making his claim, such as had never been made by mortal man. He had spoken of his seal, or sign. They ask now for a sign.

Wesley's Notes

6:30 What sign dost thou? - Amazing, after what they had just seen!

Jamieson-Fausset-Brown Bible Commentary

30. What sign showest thou, &c.-But how could they ask "a sign," when many of them scarce a day before had witnessed such a "sign" as had never till then been vouchsafed to men; when after witnessing it, they could hardly be restrained from making Him a king; when they followed Him from the one side of the lake to the other; and when, in the opening words of this very discourse, He had chided them for seeking Him, "not because they saw the signs," but for the loaves? The truth seems to be that they were confounded by the novel claims which our Lord had just advanced. In proposing to make Him a king, it was for far other purposes than dispensing to the world the bread of an everlasting life; and when He seemed to raise His claims even higher still, by representing it as the grand "work of God," that they should believe on Himself as His Sent One, they saw very clearly that He was making a demand upon them beyond anything they were prepared to accord to Him, and beyond all that man had ever before made. Hence their question, "What dost Thou work?"

Matthew Henry's Concise Commentary

6:28-35 Constant exercise of faith in Christ, is the most important and difficult part of the obedience required from us, as sinners seeking salvation. When by his grace we are enabled to live a life of faith in the Son of God, holy tempers follow, and acceptable services may be done. God, even his Father, who gave their fathers that food from heaven to support their natural lives, now gave them the true Bread for the salvation of their souls. Coming to Jesus, and believing on him, signify the same. Christ shows that he is the true Bread; he is to the soul what bread is to the body, nourishes and supports the spiritual life. He is the Bread of God. Bread which the Father gives, which he has made to be the food of our souls. Bread nourishes only by the powers of a living body; but Christ is himself living Bread, and nourishes by his own power. The doctrine of Christ crucified is now as strengthening and comforting to a believer as ever it was. He is the Bread which came down from heaven. It denotes the Divinity of Christ's person and his authority; also, the Divine origin of all the good which flows to us through him. May we with understanding and earnestness say, Lord, evermore give us this Bread.