Matthew Henry on Provebs 16:1, 9

Verse 1
As we read this, it teaches us a great truth, that we are not sufficient of ourselves to think or speak any thing of ourselves that is wise and good, but that all our sufficiency is of God, who is with the heart and with the mouth, and works in us both to will and to do, Phi 2:13; Psa 10:17. But most read it otherwise: The preparation of the heart is in man (he may contrive and design this and the other) but the answer of the tongue, not only the delivering of what he designed to speak, but the issue and success of what he designed to do, is of the Lord. That is, in short, 1. Man purposes. He has a freedom of thought and a freedom of will permitted him; let him form his projects, and lay his schemes, as he thinks best: but, after all, 1. God disposes. Man cannot go on with his business without the assistance and blessing of God, who made man's mouth and teaches us what we shall say. Nay, God easily can, and often does, cross men's purposes, and break their measures. It was a curse that was prepared in Balaam's heart, but the answer of the tongue was a blessing.

Verse 9
Man is here represented to us, 1. As a reasonable creature, that has the faculty of contriving for himself: His heart devises his way, designs an end, and projects ways and means leading to that end, which the inferior creatures, who are governed by sense and natural instinct, cannot do. The more shame for him if he do not devise the way how to please God and provide for his everlasting state. 2. But as a depending creature, that is subject to the direction and dominion of his Maker. If men devise their way, so as to make God's glory their end and his will their rule, they may expect that he will direct their steps by his Spirit and grace, so that they shall not miss their way nor come short of their end. But let men devise their worldly affairs ever so politely, and with ever so great a probability of success, yet God has the ordering of the event, and sometimes directs their steps to that which they least intended. The design of this is to teach us to say, If the Lord will, we shall live and do this or that (Jam 4:14, Jam 4:15), and to have our eye to God, not only in the great turns of our lives, but in every step we take. Lord, direct my way, 1Th 3:11.