So teach [us] to number our days, that we may apply [our] hearts unto wisdom.
Ver. 12. So teach us to number our days] The philosopher affirms, that man is therefore the wisest of creatures, because he alone can number, Bruta non numerant. But in this divine arithmetic of numbering our days (to the which all other is not to be compared, no, though we could, as Archimedes boasted, number the stars of heaven, or the sands by the sea shore), God himself must be our teacher, or we shall never do it to purpose. R. Solomon observeth, that the word כן rendered "so" here, if taken as numeral letters, maketh seventy, and the years of our life are seventy; out of which, say other Rabbis, if we deduct the time of childhood and youth, which is vanity, the time of sleep, repose, repast, and recreation (which is more than the one half), and the time of affliction and grief which we enjoy not, what a poor pittance will life be reduced unto!
That we may apply our hearts] Heb. that we may cause them to come; for naturally they hang off, and make strange.
Unto wisdom] To the true fear of God, and mortification of sin, which is the sting of death, and makes it a trap door to hell. This is hard to do, but must be done; or men are undone for ever. To live with dying thoughts is the way to die with living comforts.