Around here we often say that God’s sovereignty establishes man’s responsibility. And that is true. In his comments on Genesis 43 Calvin makes some insightful observations about these things, along with some practical applications.
3. From the example of Jacob let us learn patient endurance, should the Lord often compel us, by pressure of circumstances, to do many things contrary to the inclination of our own minds; for Jacob sends away his son, as if he were delivering him over unto death.
11. And now, having commanded his sons to do what he thought necessary, he has recourse to prayer, that God would give them favor with the governor of Egypt. We must attend to both these points whenever we are perplexed in any business; for we must not omit any of those things which are expedient, or which may seem to be of use; and yet we must place our reliance upon God. For the tranquillity of faith has no affinity with indolence: but he who expects a prosperous issue of his affairs from the Lord, will, at the same time, look closely to the means which are in his power, and will apply them to present use. Meanwhile, let the faithful observe this moderation, that when they have tried all means, they still ascribe nothing to their own industry. At the same time, let them be certainly convinced that all their endeavors will be in vain, unless the Lord bless them.
It is to be observed, also, in the form of his supplication, that Jacob regards the hearts of men as subject to the will of God. When we have to deal with men, we too often neglect to look unto the Lord, because we do not sufficiently acknowledge him as the secret governor of their hearts. But to whatever extent unruly men may be carried away by violence, it is yet certain that their passions are turned by God in whatever direction he pleases, so that he can mitigate their ferocity as often as he sees good; or can permit those to become cruel, who before were disposed to mildness. So Jacob, although his sons had found an austere severity in Joseph, yet trusts that his heart will be so in the hand of God, that it shall be suddenly mounded to humanity. Therefore, as we must hope in the Lord, when men deal unjustly with us, and must pray that they may be changed for the better; so, on the other hand, we must remember that, when they act with severity towards us, it is not done without the counsel of God.
Italics added for emphasis.