Albert Barnes Commentary Psalms 105:17

"He sent a man before them; Joseph was sold for a servant:" — Psalms 105:17 (ASV)

He sent a man before them—That is, He so ordered it by His providence that a man—Joseph—was sent before the family of Jacob into Egypt, so that he could make arrangements for their reception and preservation. The whole matter was as though God had sent him, or had commanded him to go.

And yet it was brought about as the result of a series of acts of the most wicked character: by the envy and the hatred of his brothers; by their guilt and hardness of heart in proposing at first to put him to death, and then in their arrangements for selling him into hopeless slavery; by their plan to dispose of him in such a way that their father might never hear of him again, and that they would not be troubled with him anymore. God did not cause these acts. He did not command them; He did not approve of them. And yet, since they did occur, and since Joseph’s brothers were so wicked, God made use of these things to accomplish His own benevolent purposes, and to carry out His great designs.

So He makes use of the passions of wicked people at all times to execute His plans (compare the notes at Isaiah 10:5-7); and so He will do to the end of time. People are free in their wickedness; but God is equally free in frustrating their schemes and overruling their designs for the accomplishment of His own purposes.

Who was sold for a servant—For a slave; Genesis 37:28, Genesis 37:36; Genesis 39:1.