This psalm is entitled a prayer of Moses. Where, and in what volume, it was preserved from Moses's time till the collection of psalms was begun to be made, is uncertain; but, being divinely inspired, it was under a special protection: perhaps it was written in the book of Jasher, or the book of the wars of the Lord. Moses taught the people of Israel to pray, and put words into their mouths which they might make use of in turning to the Lord. Moses is here called the man of God, because he was a prophet, the father of prophets, and an eminent type of the great prophet. In these verses we are taught,

I.To give God the praise of his care concerning his people at all times, and concerning us in our days (Psa 90:1): Lord, thou hast been to us a habitation, or dwelling-place, a refuge or help, in all generations. Now that they had fallen under God's displeasure, and he threatened to abandon them, they plead his former kindnesses to their ancestors. Canaan was a land of pilgrimage to their fathers the patriarchs, who dwelt there in tabernacles; but then God was their habitation, and, wherever they went, they were at home, at rest, in him. Egypt had been a land of bondage to them for many years, but even then God was their refuge; and in him that poor oppressed people lived and were kept in being. Note, True believers are at home in God, and that is their comfort in reference to all the toils and tribulations they meet with in this world. In him we may repose and shelter ourselves as in our dwelling-place.

II.To give God the glory of his eternity (Psa 90:2): Before the mountains were brought forth, before he made the highest part of the dust of the world (as it is expressed, Pro 8:26), before the earth fell in travail, or, as we may read it, before thou hadst formed the earth and the world (that is, before the beginning of time) thou hadst a being; even from everlasting to everlasting thou art God, an eternal God, whose existence has neither its commencement nor its period with time, nor is measured by the successions and revolutions of it, but who art the same yesterday, today, and for ever, without beginning of days, or end of life, or change of time. Note, Against all the grievances that arise from our own mortality, and the mortality of our friends, we may take comfort from God's immortality. We are dying creatures, and all our comforts in the world are dying comforts, but God is an everliving God, and those shall find him so who have him for theirs.

III.To own God's absolute sovereign dominion over man, and his irresistible incontestable power to dispose of him as he pleases (Psa 90:3): Thou turnest man to destruction, with a word's speaking, when thou pleasest, to the destruction of the body, of the earthly house; and thou sayest, Return, you children of men. 1. When God is, by sickness or other afflictions, turning men to destruction, he does thereby call men to return unto him, that is, to repent of their sins and live a new life. This God speaketh once, yea, twice. "Return unto me, from whom you have revolted," Jer 4:1. 2. When God is threatening to turn men to destruction, to bring them to death, and they have received a sentence of death within themselves, sometimes he wonderfully restores them, and says, as the old translation reads it, Again thou sayest, Return to life and health again. For God kills and makes alive again, brings down to the grave and brings up. 3. When God turns men to destruction, it is according to the general sentence passed upon all, which is this, "Return, you children of men, one, as well as another, return to your first principles; let the body return to the earth as it was (dust to dust, Gen 3:19) and let the soul return to God who gave it," Ecc 12:7. 4. Though God turns all men to destruction, yet he will again say, Return, you children of men, at the general resurrection, when, though a man dies, yet he shall live again; and "then shalt thou call and I will answer (Job 14:14, Job 14:15); thou shalt bid me return, and I shall return." The body, the soul, shall both return and unite again.

IV.To acknowledge the infinite disproportion there is between God and men, Psa 90:4. Some of the patriarchs lived nearly a thousand years; Moses knew this very well, and had recorded it: but what is their long life to God's eternal life? "A thousand years, to us, are a long period, which we cannot expect to survive; or, if we could, it is what we could not retain the remembrance of; but it is, in thy sight, as yesterday, as one day, as that which is freshest in mind; nay, it is but as a watch of the night," which was but three hours. 1. A thousand years are nothing to God's eternity; they are less than a day, than an hour, to a thousand years. Betwixt a minute and a million of years there is some proportion, but betwixt time and eternity there is none. The long lives of the patriarchs were nothing to God, not so much as the life of a child (that is born and dies the same day) is to theirs. 2. All the events of a thousand years, whether past or to come, are as present to the Eternal Mind as what was done yesterday, or the last hour, is to us, and more so. God will say, at the great day, to those whom he has turned to destruction, Return - Arise you dead. But it might be objected against the doctrine of the resurrection that it is a long time since it was expected and it has not yet come. Let that be no difficulty, for a thousand years, in God's sight, are but as one day. Nullum tempus occurrit regi - To the king all periods are alike. To this purport these words are quoted, Pe2 3:8.

V.To see the frailty of man, and his vanity even at his best estate (Psa 90:5, Psa 90:6): look upon all the children of men, and we shall see, 1. That their life is a dying life: Thou carriest them away as with a flood, that is, they are continually gliding down the stream of time into the ocean of eternity. The flood is continually flowing, and they are carried away with it; as soon as we are born we begin to die, and every day of our life carries us so much nearer death; or we are carried away violently and irresistibly, as with a flood of waters, as with an inundation, which sweeps away all before it; or as the old world was carried away with Noah's flood. Though God promised not so to drown the world again, yet death is a constant deluge. 2. That it is a dreaming life. Men are carried away as with a flood and yet they are as a sleep; they consider not their own frailty, nor are aware how near they approach to an awful eternity. Like men asleep, they imagine great things to themselves, till death wakes them, and puts an end to the pleasing dream. Time passes unobserved by us, as it does with men asleep; and, when it is over, it is as nothing. 3. That it is a short and transient life, like that of the grass which grows up and flourishes, in the morning looks green and pleasant, but in the evening the mower cuts it down, and it immediately withers, changes its colour, and loses all its beauty. Death will change us shortly, perhaps suddenly; and it is a great change that death will make with us in a little time. Man, in his prime, does but flourish as the grass, which is weak, and low, and tender, and exposed, and which, when the winter of old age comes, will wither of itself: but he may be mown down by disease or disaster, as the grass is, in the midst of summer. All flesh is as grass.

For a thousand years in thy sight are but as yesterday,.... Which may be said to obviate the difficulty in man's return, or resurrection, from the dead, taken from the length of time in which some have continued in the grave; which vanishes, when it is observed, that in thy sight, esteem, and account of God, a thousand years are but as one day; and therefore, should a man lie in the grave six or seven thousand years, it would be but as so many days with God; wherefore, if the resurrection is not incredible, as it is not, length of time can be no objection to it. Just in the same manner is this phrase used by the Apostle Peter, and who is thought to refer to this passage, to remove an objection against the second coming of Christ, taken from the continuance of things as they had been from the beginning, and from the time of the promise of it: see Pe2 3:4, though the words aptly express the disproportion there is between the eternal God and mortal man; for, was he to live a thousand years, which no man ever did, yet this would be as yesterday with God, with whom eternity itself is but a day, Isa 43:13, man is but of yesterday, that has lived the longest; and were he to live a thousand years, and that twice told, it would be but "as yesterday when it is past"; though it may seem a long time to come, yet when it is gone it is as nothing, and can never be fetched back again:

and as a watch in the night; which was divided sometimes into three, and sometimes into four parts, and so consisted but of three or four hours; and which, being in the night, is spent in sleep; so that, when a man wakes, it is but as a moment with him; so short is human life, even the longest, in the account of God; See Gill on Mat 14:25.