Then he openeth the ears of men - Margin, as in Hebrew "revealeth," or "uncovereth." The idea is, that he then reveals to the ear of man important admonitions or counsels. He communicates valuable truth. We are not to understand this as saying that the sleeper actually hears God speak, but as the ear is the organ of hearing, it is employed here to denote that God then communicates His will to human beinigs. In what way he had access to the souls of people by dreams, it is impossible to explain.
And sealeth their instruction - literally, "In their admonition he seals;" or he affixes a seal. The idea is, that he makes the admonition or instruction as secure as if a seal were affixed to it. A seal ratified or confirmed a contract, a will, or a deed, and the sense here is, that the communications of God to the soul were as firm as if they had been ratified in like manner. Or possibly it may mean, that the warnings of God were communicated to the soul like a sealed letter or message unknown to any other; that is, were made privately to the individual himself in the slumbers of the night. Others have understood the word rendered instruction, as denoting castigation, or punishment, and according to that explanation the meaning would be, that he announces to them certain punishment if they continued in sin; he made it as certain to them as if it were ratified by a seal. So Rosenmuller and Mercer. Schultens supposes it to be equivalent to inspires them, or communicates instruction by inspiration as if it were confirmed and ratified by a seal. He observes that the Arabic word hhatham is often used in the Koran, meaning to inspire. The Septuagint renders it, ἀυτοὺς ἐξεφόβησεν autous exephobēsen - "he terrifies them" - where they evidently read יחתם yechathēm instead of יחתם yachthom. The sense is, that God communicates warnings to people on their beds, in a manner as solemn and impressive as if it were ratified with a seal, and made as secure as possible.

III. By secret Inspirations
Then he openeth the ears of men, and sealeth, etc. - A dream or a vision simply considered is likely to do no good; it is the opening of the understanding, and the pouring in of the light, that make men wise to salvation. Serious alarms, holy purposes, penitential pangs for past sins, apprehension of death and judgment, discoveries of God's justice, of Christ's love, of the world's vanity, of heaven's excellence, etc., etc., etc., are often used by the Divine Spirit to withdraw men from their evil purpose, and to hide pride from man, Job 33:17; and of all these openings of the ear of the heart, and sealing instructions upon the conscience, we have numerous examples in the history of the Church, in the experience of good men, and even in the civil and providential history of all nations.

Then he openeth the ears of men, and (h) sealeth their instruction,
(h) That is, determined to send on them.

Then he openeth the ears of men,.... Not the ears of his body, which remaining shut while things are presented to his mind in a dream or vision, but his internal ears; it is the same with opening the heart or understanding to attend to and receive the things delivered in this visionary way:
and sealeth their instruction; sends home the instruction given in this manner, and imprints it upon the mind, so that it is well remembered when awake, not only the dreams themselves, but the lessons taught and learnt there, as may be observed in the cases of Abimelech and Laban, Genesis 20:3; the word signifies "chastisement" (l) as well as instruction, that being one way in which God teaches and instructs men, Psalm 94:12; and so the sense may be, that God in a dream or vision makes it known to men, that if they regard not what he says to them, and repent not of their evils, and turn from them, he will correct and chastise them, and this he assures them of; and they may look for the certain performance of it, that he will visit their transgressions with a rod, and their iniquities with stripes; things that are sealed being sure and firm. Mr. Broughton renders the words, "and imprints why they are chastised."
(l) "disciplinam eorum", Tigurine version; "castigationem eorum", Beza, Vatablus, Drusius, Mercerus, Piscator, Michaelis, Schultens.

Literally, "sealeth (their ears) to Himself by warnings," that is, with the sureness and secrecy of a seal He reveals His warnings [UMBREIT]. To seal up securely (Job 37:7).

Sealeth - He imprints those instructions upon their minds.