Isaiah 48:17
17 Thus saith the LORD, thy Redeemer, the Holy One of Israel; I am the LORD thy God which teacheth thee to profit, which leadeth thee by the way that thou shouldest go.
It is not only the commercial world which has to make its calculations of profit and loss. All life is made up of profit and loss. And if there is not profit, there is loss; and if there is not loss, there is profit.
I. I understand the text to mean, not that God teaches us in a profitable way, but that He instructs us how to get the profit in all things; that He gives that faculty the power to take the good and refuse the evil; to imbibe the honey and reject the poison.
II. Consider how God does "teach to profit." (1) The first thing which God will probably teach and which we must receive is a general confidence that there is a profit, however imperceptible it may be at the time to us, in the thing which He is sending to us. (2) This faith given, the next thing that God puts into our hearts is to seek that good; eternal profit, profit both to ourselves and to Him, in that He is glorified in His own work. We are to look for that profit, not on the surface, but in certain deeper, hidden meanings and intentions which lie underneath. Into those deeper meanings God will lead and admit you. But not without three things: a reverent acceptance of His teaching, hard work, and a good life. These are God's three conditions in all His teaching, from which He never departs. You must love the teaching; you must work the teaching out with great pains and at any cost; and you must do His will.
J. Vaughan, Sermons,13th series, p. 21.
References: Isaiah 48:17. W. J. Mayers, Christian World Pulpit,vol. xvii., p. 228. Isaiah 48:17; Isaiah 48:18. Preacher's Monthly,vol. ix., p. 47. Isaiah 48:18. A. Raleigh, Christian World Pulpit,vol. xiv., p. 369 (see also Old Testament Outlines,p. 208); Spurgeon, Sermons,vol. xi., No. 610; W. Steadman, Christian World Pulpit,vol. iv., p. 152; Homiletic Quarterly,vol. i., p. 553; J. Keble, Sermons from Advent to Christmas Eve,p. 414; J. N. Norton, Every Sunday,p. 401.