Ephesians 3:8

Unto me who am less than the least of all saints
This is an instance of the great humility of the apostle, and indeed the greatest saints are generally speaking, the most humble souls, as Abraham, Jacob, Moses, David, and others; these have the meanest thoughts of themselves, and the best of others; they rejoice in the grace of God manifested to others; they are willing to receive instruction, nay admonition, from the meanest believer; they have the least opinion of their own works, and are the greatest admirers of the grace of God; and do most contentedly submit to the sovereign will of God: the reasons of their great humility are, because they have the largest discoveries of the love and grace of God and Christ, which are of a soul humbling nature; they are the most sensible of their own sinfulness, vileness, and unworthiness, which keeps them low in their own sight; they are commonly the most afflicted with Satan's temptations, which are suffered to attend them, lest they should be exalted above measure; they are the most fruitful souls, and boughs laden with fruit hang lowest; and they are the most conformable to Christ, who is meek and lowly. The phrase seems to be Jewish: there was one R. Jose "the little", who was so called, it is said, because he was (Mydyox Njq) , "the least of saints" ^F12: but the apostle uses a still more diminutive word, and calls himself less than the least of them; and adds,

is this grace given;
that is, the gift of grace, as before, the ministerial gift:

that I should preach among the Gentiles the unsearchable riches
of Christ;
the riches of Christ, as God, lie in the perfections of his nature, in the works of his hands, in his empire and dominion over all, and in the revenues of glory, which result from thence; and these riches are underived and incommunicable, and are ineffable, yea inconceivable: his riches, as Mediator, lie in the persons of the elect, in the grace that is laid up in him for them, called the riches of grace, and in the inheritance he is possessed of for them, called the riches of glory; and these rich things are communicable, as well as solid, satisfying, and lasting; and they are unsearchable to the natural man, and cannot be fully investigated by believers themselves; they will be telling over to all eternity: and they will appear unsearchable, when it is considered what they have procured, and what blessings have been dispensed according to them; what a large family Christ has maintained by them, and how richly and fully he has provided for them, and to what honour and grandeur he raises them all. Now it was great grace to intrust the apostle with such a ministry, to put such treasure into an earthen vessel; it was great grace that qualified him for it; and it was great grace in particular to the Gentiles, that he should be appointed to publish these among them; and so the apostle esteemed it, and himself unworthy of such honour.