He [the Lord] made him [Jacob] ride on the high places of the land, and he ate the produce of the field, and he suckled him with honey out of the rock, and oil out of the flinty rock. (Dt 32:13)
But he would feed you with the finest of the wheat, and with honey from the rock I would satisfy you. (Ps 81:16)
There is a very short answer to the imagery of the honey from the rock: honey is the word of God, and the rock is Christ. Christ came as the ultimate word from the father. He is the ultimate revelation of God. All of God's word finds its focus in him.
But there is a longer answer. For the imagery of the rock is another of those frequently occurring motifs in Scripture that is highly significant. God is frequently referred to as the Rock in the Old Testament, so Christ as the Rock (1Co 10:4) is an obvious reference to his deity. But interestingly, Abraham is also referred to as a rock:
Listen to me, you who pursue righteousness, you who seek the Lord: look to the rock from which you were hewn, and to the quarry from which you were dug. Look to Abraham your father and to Sarah who bore you; for he was but one when I called him, that I might bless him and multiply him. (Isa 51:1-2)
Abraham became Israel. He was one man when he was called, and he responded to a personal call, but he was driven by his corporate vision of the city of God, and he became a people belonging to God.
The rock in this context represents the eternal kingdom purpose of God: to take hold of a man, and through him to fill the earth with his people.
It is not just Abraham, but all those to whom God made a covenant express this unchanging purpose. Adam was one man whom God commissioned to fill the earth. As was Noah; as was Abraham. In Moses and David too we see a covenant to a man which is to have an outworking to all God's people.
This is the same imagery and the same great kingdom purpose we see in the wonderful second chapter of the prophet Daniel. A rock cut from the heavenly mountain, that impacts the earth and grows until that same mountain is reproduced in all the earth.
For all the covenants, and the kingdom purpose of God find their fulfilment in Christ. He is the true fulfilment of the rock. One man through whom God will produce a people who will fill the earth with the knowledge of his glory.
Honey from the rock is thus the message of Christ and his kingdom. The message of the Kingdom; the good news of the kingdom; the gospel of the kingdom; the gospel.
(It is important that we remember that the gospel is the gospel of the kingdom. It is not the gospel of the individual. Christ's message was not "Repent, and come into all the blessings of God." - though that is indeed the case - but, "Repent, for the Kingdom of God is at hand." It is not a call to self-improvement, but a call for self-denial for a cause that is bigger than any individual.)
Honey from the rock is not just meant to nourish us, but to be exported by us to the ends of the earth. As the rock that is the kingdom grows to fill the earth, so too the honey from the rock must flow from this mountain to touch all mankind.
And this gospel of the kingdom will be proclaimed throughout the whole world as a testimony to all nations, and then the end will come. (Mtt 24:14)