"When the Law drives you to the point of despair, let it drive you a little farther, let it drive you straight into the arms of Jesus who says: 'Come unto me, all ye that labour and are heavy laden, and I will give you rest.'"

      Martin Luther, Lectures on Galatians 3:19, "The Law was added because of transgressions," as heavily paraphrased from 1937 by Theodore Graebner, who was willing to undertake the project proposed by P. J. Zondervan only if "permitted to make Luther talk American, 'streamline' him, so to speak— . . . make him talk as he would talk today to Americans."  The giveaway is the double clause "let it drive you a little farther, let it drive you straight into the arms of Jesus".  For here is how that same passage reads on pp. 315-316 of the far more reliable LW 26:

"Therefore we do not abolish the Law; but we show its true function and use, namely, that it is a most useful servant impelling us to Christ. After the Law has humbled, terrified, and completely crushed you, so that you are on the brink of despair, then see to it that you know how to use the Law correctly; for its function and use is not only to disclose the sin and wrath of God but also to drive us to Christ. None but the Holy Spirit is intent on this use of the Law or preaches the Gospel, because nothing but the Gospel says that God is present with those who are contrite in heart (Is. 57:15). 

"Therefore if you have been crushed by that hammer, do not use your contrition wrongly by burdening yourself with even more laws. Listen to Christ when He says (Matt. 11:28): 'Come to Me, all who labor and are heavy laden, and I will give you rest.' When the Law drives you this way, so that you despair of everything that is your own and seek help and solace from Christ, then it is being used correctly; and so, through the Gospel, it serves the cause of justification. This is the best and most perfect use of the Law."