John Calvin's Bible Commentary
Psalms 105:20
20.The king sent and loosed him The Psalmist celebrates in high terms the deliverance of Joseph; for God’s singular power was conspicuously displayed in a matter so incredible. What is of more rare occurrence than for a most powerful monarch to bring a stranger out of prison to constitute him ruler over his whole kingdom, and to raise him to a rank of honor, second only to himself? The phrase in verse 22, to bind his princes, is commonly explained as implying that Joseph was invested with the chief sovereignty in the administration of the government, so that he could cast into prison, at his pleasure, even the nobles of the realm. Others, conceiving this interpretation to be somewhat harsh, derive the verb לאסור, lesor, which Moses employs, not from אסר, asar, which signifies to bind, but from יסר, yasar, which signifies to instruct, by changing the letter י, yod, into א, aleph. (218) But I am surprised that neither of them have perceived the metaphor contained in this word, which is, that Joseph held the lords of Egypt bound to him at his pleasure, or subject to his power. What is here spoken of is not fetters, but the bond or obligation of obedience, both the princes and all others being dependent on his will. The expression, which is added a little after, to teach his elders wisdom, evinces that Joseph did not bear sway like a tyrant, difficult and rare a thing as it is for men, when invested with sovereign power, not to give loose reins to their own humor: but that he was a rule and a pattern, even to the chief of them, in the high degree of discretion which he exemplified in the administering the affairs of state.