John 6:27

Labour not for the meat which perisheth
Meaning either food for the body, which is perishing; its virtue is perishing; man cannot live by it alone, nor does it last long; its substance is perishing; it is received into the stomach, and there digested; it goes into the belly, and is cast out into the draught; and that which it supports, for a while, is perishing; and both the one, and the other, shall be destroyed; even meats for the belly, and the belly for meats: now, though it becomes men to work for their bread, to provide it for themselves and families; yet they should not be anxiously solicitous about it, or labour only for that, and prefer it to spiritual food: or else food for the mind is meant, and that either in a sensual way, as sinful lust and pleasures, the honours of this world, and the riches of it; which are sweet morsels, though bread of deceit, to carnal minds, and which they labour hard for: or, in a religious way, as superstition, will worship, external works of righteousness, in order to please God, and obtain eternal life and salvation; which to labour for in such a way, is to spend money for that which is not bread, and labour for that which profiteth not; and in each of these ways were these Jews labouring for perishing food, from which Christ dissuades them:

but for that which endureth unto everlasting life;
either the grace of Christ, which, as meat, is quickening and refreshing, strengthening and supporting, and which causes nourishment and growth, and by virtue of which work is done; and this springs up unto everlasting life, and is inseparably connected with it; and particularly the blessings of grace, such as sanctification, adoption, pardon, and justification: or the Gospel, and the ordinances of it, which are refreshing, and strengthening, and by which the saints are nourished up unto everlasting life; or rather the flesh of Christ eaten, in a spiritual sense, by faith, of which Christ so largely discourses in the following part of the chapter:

which the son of man shall give unto you;
meaning either everlasting life, which is in Christ's gift, and is a free grace gift of his; or else the meat which endures unto it: for though it is to be laboured for, not so as to prepare it, or to purchase it, but by asking for it in prayer, and by attending on ordinances, and exercising faith on Christ; yet it is his gift, and he gives it freely; grace, and the blessings of it, are freely given by him, and so are the Gospel and its ordinances; and also his own flesh, which is first given by him, by way of sacrifice, in the room and stead of his people, and for the life of them, ( John 6:51 ) ; and then it is given unto them to feed upon spiritually by faith, and which is here designed:

for him hath God the Father sealed;
designated and appointed to be the Saviour, and Redeemer of his people, and has sent, authorized, and commissioned him as such; and has made him known, and approved of him, by the descent of the Spirit on him, and by a voice from heaven, declaring him his beloved Son; and has confirmed him to be the Messiah by the miraculous works he gave him to finish; for all which several uses seals are, as to distinguish one thing from another, to render anything authentic, to point it out, or to confirm it.