The reward of the inheritance - Here, ye have neither lands nor property; ye are servants or slaves; be not discouraged, ye have an inheritance in store; be faithful unto God and to your employers, and Christ will give you a heavenly inheritance.

Knowing that of the Lord ye shall receive the (p) reward of the inheritance: for ye serve the Lord Christ.
(p) Because you will have duly obeyed your masters, the time will come, that you will be changed from servants to sons, and you will know this for certain, which will be when you are made partakers of the heavenly inheritance.

Knowing that of the Lord ye shall receive the reward of the inheritance,.... This is said for the encouragement of Christian servants, who, though they may receive little or nothing from their earthly and carnal masters; yet they shall be used and treated as children by the Lord, and by whom they will be possessed of an eternal inheritance, after their work and labour is over: by "the reward of the inheritance" is meant the heavenly glory, called a reward, because the apostle is speaking to servants and therefore uses language agreeable to them; and who, though they may have no reward in this world, yet as there is a God that judgeth in the earth, there is verily one for them in the world to come: and though it is not given for working, yet it is given to those that do good, and continue in well doing; whose works follow, though they do not go before them; and is enjoyed after their work is over, as the servant receives his wages at evening and when he has done his work; though this will not be received as a reward of debt, but of grace; it cannot be of merit, as is clear from the nature of good works themselves, which are all due, to God, prior to the performance of them; and when done in the best manner, are no more than a man's duty, and are done not in his own strength, but by the grace of God; and in many things, yea in everything, he comes short of performing what is incumbent on him; and besides, there is no manner of proportion between: the best services of the saints, and eternal glory: to which may be added, that eternal life is the free gift of their heavenly Father to them, and is here called an inheritance, which never becomes the property of servants in a way of merit, but is the portion of children, from their Father's good pleasure. Wherefore the heavenly glory is such a reward as that it is an "inheritance"; or, as the Syriac version renders it, "in an inheritance"; it lies in an inheritance, an inheritance incorruptible and undefiled, that fades not away, reserved in the heavens; and which is not got by industry, or obtained by the works of the law, nor bought with a price, but is a free bequest of God as a Father to his children; for an inheritance is peculiar to children, and this to the children of God, as these believing servants were; and which comes to them by and through the death of the testator; and it may be called an inheritance, because the heavenly glory is substantial, it is substance, a better and a more enduring substance than any inheritance in this world; and is a very plentiful possession and estate, it consists of all things, yea, God himself is the portion of his people, and they that are his children are heirs of God; there is not only a glory, but riches of glory, a plenty, a fulness of it in this inheritance; the way in which they come by it, is receiving it from Christ; "of the Lord ye shall receive it". It is in a way of receiving, and so by gift, as a man can receive nothing but what is given him; and as all grace is in a way of receiving, and therefore boasting in it is excluded, so glory is enjoyed in the same way, and from the same hands, even from Christ, the righteous Judge, that will give it; it is in him they obtain this inheritance, and are in him chosen and predestinated unto it; it is by his resurrection from the dead, and in consequence of it, that they through the power of his Spirit and grace are begotten unto it; it is his grace that makes them meet for it; and he has it in his hands for them; he is a feoffee in trust on their behalf, and is able to give it to them; and will at the last day introduce them into the full possession of it. Now these Christian servants "knowing" all this, having a lively hope of this inheritance, a full persuasion, and a firm faith of right unto it, and meetness for it, and having the Spirit of God as an earnest and pledge of it; the consideration of it must greatly tend to make them quiet and easy in their present servitude, and to encourage them, to the discharge of their duty with diligence, faithfulness, and cheerfulness: since they might assure themselves of the inheritance hereafter, how small soever their reward was now:
for ye serve the Lord Christ; who is a good master, and faithful to all his engagements and promises, all whose servants are respected by him, and honoured by his Father, and shall be for ever where he is.

the reward of the inheritance--"Knowing that it is from the Lord (the ultimate source of reward), ye shall receive the compensation (or recompense, which will make ample amends for your having no earthly possession as slaves now) consisting of the inheritance" (a term excluding the notion of meriting it by works: it is all of grace, Romans 4:14; Galatians 3:18).
for ye serve--The oldest manuscripts omit "for," then translate as Vulgate, "Serve ye the Lord Christ;" compare Colossians 3:23, "To the Lord and not unto men" (1-Corinthians 7:22-23).