The Lord Jehovah hath opened mine ear. He again repeats what he had formerly said, and here includes everything that belongs to the office of a teacher; for the "opening of the ear" must be understood to refer not only to doctrine, but to the whole calling; that is, when he takes one to be his servant, and intbrms of his duty him whom he has determined to send, when he gives commands, and enjoins him to execute what he commands. But the Lord "opens the ear," not only when he declares what is his will, but when he powerfully affects a man's heart and moves him to render obedience, as it is said, "Thou hast bored mine ear." (Psalm 40:6.) And Christ says, "Whosoever hath heard and learned from the Father cometh to me." (John 6:45.) Such is also the import of the second clause, And I was not rebellious, the meaning of which may be thus summed up: "He undertakes nothing at random, but, being fully convinced of God's calling, he discharges the office of a teacher, though it is laborious and difficult, because he is ready to obey."

The Lord God hath opened mine ear - This is another expression denoting that he was attentive to the import of the divine commission (see Psalm 40:6).
And I was not rebellious - I willingly undertook the task of communicating the divine will to mankind. The statement here is in accordance with all that is said of the Messiah, that he was willing to come and do the will of God, and that whatever trials the work involved he was prepared to meet them (see Psalm 40:6-8; compare Hebrews 10:4-10).

Neither turned away back "Neither did I withdraw myself backward" - Eleven MSS. and the oldest edition prefix the conjunction ו vau; and so also the Septuagint and Syriac.

The Lord God hath opened mine ear,.... To hear most freely, and receive most fully, what is said by him, and to observe and do it: the allusion seems to be to the servant that had his ears bored, being willing to serve his master for ever, Exodus 21:5 which phrase of boring or opening the ear is used of Christ, Psalm 40:6. It is expressive of his voluntary obedience, as Mediator, to his divine Father, engaging in, and performing with the greatest readiness and cheerfulness, the great work of man's redemption and salvation.
And I was not rebellious; not to his earthly parents, to whom he was subject; nor to civil magistrates, to whom he paid tribute; nor to God, he always did the things that pleased him: he was obedient to the precepts of the moral law, and to the penalty of it, death itself, and readily submitted to the will of God in suffering for his people; which obedience of his was entirely free and voluntary, full, complete, and perfect, done in the room and stead of his people; is the measure of their righteousness, and by which they become righteous; is well pleasing to God, and infinitely preferable to the obedience of men and angels:
neither turned away back; he did not decline the work proposed to him, but readily engaged in it; he never stopped in it, or desisted from it, until he had finished it; he did not hesitate about it, as Moses and Jeremy; or flee from it, as Jonah.

opened . . . ear--(See on Isaiah 42:20; Isaiah 48:8); that is, hath made me obediently attentive (but MAURER, "hath informed me of my duty"), as a servant to his master (compare Psalm 40:6-8, with Philippians 2:7; Isaiah 42:1; Isaiah 49:3, Isaiah 49:6; Isaiah 52:13; Isaiah 53:11; Matthew 20:28; Luke 22:27).
not rebellious--but, on the contrary, most willing to do the Father's will in proclaiming and procuring salvation for man, at the cost of His own sufferings (Hebrews 10:5-10).

His calling is to save, not to destroy; and for this calling he has Jehovah as a teacher, and to Him he has submitted himself in docile susceptibility and immoveable obedience. Isaiah 50:5 "The Lord Jehovah hath opened mine ear; and I, I was not rebellious, and did not turn back." He put him into a position inwardly to discern His will, that he might become the mediator of divine revelation; and he did not set himself against this calling (mârâh, according to its radical meaning stringere, to make one's self rigid against any one, ἀντιτείνειν), and did not draw back from obeying the call, which, as he well knew, would not bring him earthly honour and gain, but rather shame and ill-treatment. Ever since he had taken the path of his calling, he had not drawn timidly back from the sufferings with which it was connected, but had rather cheerfully taken them upon him. V.6 "I offered my back to smiters, and my cheeks to them that pluck off the hair; I hid not my face from shame and spitting." He offered his back to such as smote it, his cheeks to such as plucked out the hair of his beard (mârat as in Nehemiah 13:25). He did not hide his face, to cover it up from actual insults, or from being spit upon (on kelimmōth with rōq, smiting on the cheek, κολαφίζειν, strokes with rods, ῥαπίζειν, blows upon the head, τύπτειν εἰς τὴν κεφαλήν with ἐμπτύειν, compare Matthew 26:67; Matthew 27:30; John 18:22). The way of his calling leads through a shameful condition of humiliation. What was typified in Job (see Isaiah 30:10; Isaiah 17:6), and prefigured typically and prophetically in the Psalm of David (see Psalm 22:7; Psalm 69:8), finds in him its perfect antitypical fulfilment.