John Gill

The Lord is the portion of mine inheritance and of my cup,.... This is said by Christ as a priest, and in allusion to the Levitical priests, who had no inheritance in the land of Canaan with their brethren, but the Lord was their part and portion, and their inheritance, Num 18:20; and it expresses the strong love and affection Christ had for the Lord as his God, the delight and pleasure he had in him, and the satisfaction he had in the enjoyment of him and communion with him, and that it was his meat and drink to serve him, and to do his will; and though his goodness did not extend to him, yet his goodness and happiness as man lay in him: unless the sense should be, "the Lord is he who gives me the portion of mine inheritance;'' meaning his church and people, all the elect of God, who are Christ's portion and inheritance, given him by the Father; see Deu 32:9; And assigns to me my cup, as of blessings, so of sorrows and sufferings, which being measured out, filled up, and put into his hand by his Father, he freely took it, Joh 18:11; thou maintainest my lot; that is, either his interest in God himself, as his covenant God, which always continued; or the lot of goods, of grace and glory, put into his hands for his people, which always remains; or rather the saints themselves, who, as they are Christ's portion and inheritance, so they are his lot; in allusion to the land of Canaan, which was divided by lot: these Jehovah took hold of, kept, preserved, and upheld, as the word (s) signifies; so that they shall never totally and finally fall and perish; and this sense is countenanced by what follows. (s) "sustentas", Musculus, Pagninus, Junius & Tremellius, Piscator; so Ainsworth; "sustentans", Montanus, Michaelis; "tenuisti", Cocceius; "tenendo quasi sustentans", Gejerus.