So teach us to number our days - literally, “To number our days make us know, and we will bring a heart of wisdom.” The prayer is, that God would instruct us to estimate our days aright: their number; the rapidity with which they pass away; the liability to be cut down; the certainty that they must soon come to an end; their bearing on the future state of being.
That we may apply our hearts unto wisdom - Margin, “Cause to come.” We will bring, or cause to come, a heart of wisdom. By taking a just account of life, that we may bring to it a heart truly wise, or act wisely in view of these facts. The prayer is, that God would enable us to form such an estimate of life, that we shall be truly wise; that we may be able to act “as if” we saw the whole of life, or as we should do if we saw its end. God sees the end - the time, the manner, the circumstances in which life will close; and although he has wisely hidden that from us, yet he can enable us to act as if we saw it for ourselves; to have the same objects before us, and to make as much of life, “as if” we saw when and how it would close. If anyone knew when, and where, and how he was to die, it might be presumed that this would exert an important influence on him in forming his plans, and on his general manner of life. The prayer is, that God would enable us to act “as if” we had such a view.