Why do you not understand my language? In this passage, he reproaches the Jews with their obstinacy, which was so great, that they could not even endure to hear him speak Hence he infers, that they are actuated and hurried away by diabolical rage. Some make a distinction here between language and speech, as if speech had a more extensive meaning; but I do not see it; [1] and besides, it would not be appropriate that the word which means less should be placed first. Many point this verse in such a manner as to make the question close with the word language; [2] as if the question consisted only of these words, Why do you not understand my language? So that the reason is immediately assigned, Because you cannot hear my word. But I think that it ought rather to be read in immediate connection, as if he had said, "What is the reason why my speech appears to you barbarous and unknown, so that I gain nothing by speaking to you, and so that you do not even deign to open your ears to receive what I say?" In the former clause, therefore, he reproves their stupidity; in the latter, he reproves their obstinate and ungovernable hatred of his doctrine; and he afterwards assigns a reason for both, when he says, that they are sprung from the devil For by putting the question, he intended to take out of their hands what was the subject of their continual boasting, that they are led by reason and judgment to oppose him.

Footnotes

1 - "Aucuns font ici difference entre Langage et Parole, pource que la parole emporte plus, mais je n'y en voy point."

2 - "En ce mot Langage."

Why do ye not - My meaning is clear, if you were disposed to understand me.
Even because ye cannot hear my word - The word "hear" in this place is to be understood in the sense of bear or tolerate, as in John 6:60. His doctrine was offensive to them. They hated it, and hence they perverted his meaning, and were resolved not to understand him. Their pride, vanity, and wickedness opposed it. The reason why sinners do not understand the Bible and its doctrines is because they cannot bear them. They hate them, and their hatred produces want of candor, a disposition to cavil and to pervert the truth, and an obstinate purpose that it shall not be applied to their case. Hence, they embrace every form of false doctrine, and choose error rather than truth, and darkness rather than light. A disposition to believe God is one of the best helps for understanding the Bible.

Why do ye not understand my speech? - Την λαλιαν την εμην, This my mode of speaking - when illustrating spiritual by natural things: λαλια refers to the manner of speaking; λογος, to the matter or subject on which he spoke. For λαλιαν, the Codex Bezae had originally αληθειαν: why do ye not acknowledge this Truth of mine? A few other MSS. agree in this reading.
Because ye cannot hear my word - That is, ye cannot bear my doctrine: it comes too close to you; it searches your hearts, detects your hypocrisy, and exposes your iniquitous intentions and designs; and as ye are determined not to leave your sins, so ye are purposed not to hear my doctrine.

Why do ye not understand my (k) speech? [even] because ye cannot hear my word.
(k) Or, language: as though he said, "You do not understand what I say any more than if I spoke in a strange and unknown language to you."

Why do ye not understand my speech?.... Language, idiom, dialect, and form of speaking, in a figurative way; for they did not know what he meant by liberty, and bondage, and by having another father than Abraham, or by his own procession and coming forth from God:
even because ye cannot hear my word; as they had no spiritual discerning and understanding of the doctrine of Christ, which showed them to be carnal, and natural men, and not regenerate ones, and the children of God; so they had an aversion to it, and could not bear to hear it.

Ye cannot hear my word. Cannot receive it because Satan has your hearts, and is your father.

Ye cannot - Such is your stubbornness and pride, hear - Receive, obey my word. Not being desirous to do my will, ye cannot understand my doctrine, John 7:17.