Our Lord next warned against hypocrisy and outward show in religious duties. What we do, must be done from an inward principle, that we may be approved of God, not that we may be praised of men. In these verses we are cautioned against hypocrisy in giving alms. Take heed of it. It is a subtle sin; and vain-glory creeps into what we do, before we are aware. But the duty is not the less necessary and excellent for being abused by hypocrites to serve their pride. The doom Christ passes, at first may seem a promise, but it is their reward; not the reward God promises to those who do good, but the reward hypocrites promise themselves, and a poor reward it is; they did it to be seen of men, and they are seen of men. When we take least notice of our good deeds ourselves, God takes most notice of them. He will reward thee; not as a master who gives his servant what he earns, and no more, but as a Father who gives abundantly to his son that serves him.
6But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly.
English Standard Version
6But when you pray, go into your room and shut the door and pray to your Father who is in secret. And your Father who sees in secret will reward you.
6 "Here's what I want you to do: Find a quiet, secluded place so you won't be tempted to role-play before God. Just be there as simply and honestly as you can manage. The focus will shift from you to God, and you will begin to sense his grace.
New King James Version
6 But you, when you pray, go into your room, and when you have shut your door, pray to your Father who is in the secret place; and your Father who sees in secret will reward you openly.
New Living Translation
6 But when you pray, go away by yourself, shut the door behind you, and pray to your Father in private. Then your Father, who sees everything, will reward you.
It is taken for granted that all who are disciples of Christ pray. You may as soon find a living man that does not breathe, as a living Christian that does not pray. If prayerless, then graceless. The Scribes and Pharisees were guilty of two great faults in prayer, vain-glory and vain repetitions. "Verily they have their reward;" if in so great a matter as is between us and God, when we are at prayer, we can look to so poor a thing as the praise of men, it is just that it should be all our reward. Yet there is not a secret, sudden breathing after God, but he observes it. It is called a reward, but it is of grace, not of debt; what merit can there be in begging? If he does not give his people what they ask, it is because he knows they do not need it, and that it is not for their good. So far is God from being wrought upon by the length or words of our prayers, that the most powerful intercessions are those which are made with groanings that cannot be uttered. Let us well study what is shown of the frame of mind in which our prayers should be offered, and learn daily from Christ how to pray.
Religious fasting is a duty required of the disciples of Christ, but it is not so much a duty itself, as a means to dispose us for other duties. Fasting is the humbling of the soul, Psalm 35:13; that is the inside of the duty; let that, therefore, be thy principal care, and as to the outside of it, covet not to let it be seen. God sees in secret, and will reward openly.