To bind his princes at pleasure - Giving him absolute power. The power here referred to was that which was always claimed in despotic governments, and was, and is still, actually practiced in Oriental nations. Literally, "to bind his princes 'by his soul;'" that is, at his will; or, as he chose.
And teach his senators wisdom - This is now an unhappy translation. The word "senator" in fact originally had reference to "age" (see Webster's Dictionary), but it is now commonly applied to a body of men entrusted with a share in the administration of government - usually a higher body in a government - as the Senate of the United States. As these were usually "aged men," the word has acquired its present meaning, and is now ordinarily used without reference to age. But there was no such constituted body in the government of Egypt - for despotism does not admit of such an arrangement. The Hebrew word here means "aged men," and is employed with reference to those who were connected with the administration, or whom the monarch would consult - his counselors. The meaning of the phrase "to teach them wisdom" is, that he would instruct them "what to do;" literally, he would "make them wise," that is, in reference to the administration. He had the right of commanding them, and directing them in the administration. At the same time, it is doubtless true that Joseph was endowed with practical wisdom in the affairs of government far beyond them, and that in instructing them what to do, he actually imparted "wisdom" to them.

To bind his (m) princes at his pleasure; and teach his senators wisdom.
(m) That the very princes of the countries would be at Joseph's commandment, and learn wisdom from him.

To bind his princes at his pleasure,.... Not to lay them in prison, and bind them with fetters, as he had been bound; but to give laws unto them as he pleased, and bind and oblige them to observe them: for, according to his word, all the people of Egypt, high and low, rich and poor, were to be ruled; and, without his leave, no man was to lift up his hand or foot in all the land, Genesis 41:40. All Christ's people are princes, to whom he gives laws at his pleasure, as one having authority, though they are not grievous; and these he binds, obliges, and constrains his people by love to observe, and which they do. Jarchi's note is,
"this is an expression of love like that; and the soul of Jonathan was bound unto the soul of David: when he (Joseph) interpreted the dream, they all loved him.''
The Targum is,
"to bind his nobles as to his soul.''
And teach his senators wisdom; his elders, his privy counsellors: he made him president of his council; where he was a curb upon them, and restrained them from taking wrong or bad measures; so Schultens (i), from the use of the word in the Arabic language, renders it, "to bridle", or restrain his senators; which conveys an idea agreeable to the preceding clause. Nor were these the only persons he taught; he not only instructed the nobles and courtiers in politics, but the priests and men of learning in the arts and sciences; and all, no doubt, in the mysteries of the true religion, as he had an opportunity. And this is the source of the wisdom of the Egyptians, which Moses was afterwards brought up in; and for which that people were so famous, that many of the ancient philosophers, as Pythagoras, Plato, and others, travelled thither to acquire it. This they had from Joseph, and his people that dwelt in their land. Christ's senators are his apostles and ministers, the elders that rule well, and labour in the word and doctrine: these are taught wisdom by him; the knowledge of divine and spiritual things; the words and doctrines of the wise are all from him, that one Shepherd; that they, as undershepherds and pastors, may feed others with knowledge and understanding.
(i) De Defect. Hod. Ling. Hebrews. s. 215.

To bind--Not literally bind; but exercise over them absolute control, as the parallel in the second clause shows; also Genesis 41:40, Genesis 41:44, in which not literal fettering, but commanding obedience, is spoken of. It refers to Psalm 105:18. The soul that was once bound itself now binds others, even princes. The same moral binding is assigned to the saints (Psalm 149:8).
teach . . . senators wisdom--the ground of his exaltation by Pharaoh was his wisdom (Genesis 41:39); namely, in state policy, and ordering well a kingdom.