The {m} secret things belong unto the LORD our God: but those things which are revealed belong unto us and to our children for ever, that we may do all the words of this law.

(m) Moses by this proves their curiosity, who seek those things that are only known to God: and their negligence who do not regard that which God has revealed to them, as the law.

Wesley's Notes

29:29 The secret things - Having mentioned the amazing judgments of God upon the whole land and people of Israel, and foreseeing the utter extirpation which would come upon them for their wickedness, he breaks out into this pathetic exclamation, either to bridle their curiosity, who would be apt to enquire into the time and manner of so great an event; or to quiet his own mind, and satisfy the scruples of others, who perceiving God to deal so severely with his own people, when in the meantime he suffered those nations which were guilty of grosser atheism and idolatry, might thence take occasion to deny his providence or question the equity of his proceedings. To this he answers, that the ways and judgments of God, tho' never unjust, are often times hidden from us, unsearchable by our shallow capacities, and matter for our admiration, not our enquiry. But the things which are revealed by God and his word, are the proper object of our enquiries, that thereby we may know our duty, and be kept from such terrible calamities as these now mentioned.

Jamieson-Fausset-Brown Bible Commentary

29. The secret things belong unto the Lord-This verse has no apparent connection with the thread of discourse. It is thought to have been said in answer to the looks of astonishment or the words of inquiry as to whether they would be ever so wicked as to deserve such punishments. The recorded history of God's providential dealings towards Israel presents a wonderful combination of "goodness and severity." There is much of it involved in mystery too profound for our limited capacities to fathom; but, from the comprehensive wisdom displayed in those parts which have been made known to us, we are prepared to enter into the full spirit of the apostle's exclamation, "How unsearchable are his judgments" (Ro 11:33).

Matthew Henry's Concise Commentary

29:29 Moses ends his prophecy of the Jews' rejection, just as St. Paul ends his discourse on the same subject, when it began to be fulfilled, Ro 11:33. We are forbidden curiously to inquire into the secret counsels of God, and to determine concerning them. But we are directed and encouraged, diligently to seek into that which God has made known. He has kept back nothing that is profitable for us, but only that of which it is good for us to be ignorant. The end of all Divine revelation is, not to furnish curious subjects of speculation and discourse, but that we may do all the words of this law, and be blessed in our deed. This, the Bible plainly reveals; further than this, man cannot profitably go. By this light he may live and die comfortably, and be happy for ever.