This is Calvin's preface to the French Bible. He wrote it a year after his conversion! It's full of some wonderful things but I'll just quote him on the promises and then the patterns of Christ in the OT.
Notice that Calvin considered the Old Testament saints to have consciously understood these promises and patterns. Do read the whole thing here.
Promises of Christ:
Also from the very beginning, the world was not without the hope of recovering the loss suffered in Adam. For even Adam, in spite of his incontinency after his ruin, was given the promise that the seed of the woman would crush the head of the serpent; which is to say that Jesus Christ born of a virgin would strike down and destroy the power of Satan.
After that, this promise was renewed more fully to Abraham, when God told him that all the nations of the earth would be blessed in his seed. This meant that from his seed would come Jesus Christ according to the flesh, by whose blessing all men of every land would be sanctified. And the same promise was renewed to Isaac, in the same form and in the same words; and after that it was announced often, repeated and confirmed by the testimony of the various prophets, so as to state plainly, and most reliably, of whom Christ was to be born, at what time, in what place; what afflictions and death he was to suffer, and with what glory he was to rise from the dead; what was to be his Kingdom, and to what salvation he was to bring his own.
In the first place, it is foretold for us in Isaiah, how he was to be born of a virgin, saying: Behold, a virgin shall conceive and shall bear a son, and you shall call his name Immanuel (Isa. 7:14). The time is described for us in Moses, when good Jacob says, The scepter shall not be taken from the line of Judah, nor the government from his hand, until the coming of the One who is to be sent; and the same is the expectation of the nations (Gen. 49:10). And this was verified when Jesus Christ came into the world; for the Romans, after having divested the Jews of all government and rule, had, thirty-seven years before [the coming of Christ] ordained Herod king over them, whose father was Antipater the Edomite and his mother an Arabian; he was therefore a foreigner. It had happened sometimes before that the Jews had been without a king; but they had never before been left as they were now without counselors, rulers, and lawgivers. Another numbering [of the time of Christ's birth] is given in Daniel, by the reckoning of the seventy weeks (Dan. 9:24). The place of his birth was given us clearly by Micah, who said, And thou Bethlehem Ephrata, thou are the least among the thousands of Judah; but from thee shall come for me the One who shall reign over Israel; and his coming shall be for all the days of eternity (Micah 5:2). As for the afflictions he was to bear for our deliverance and the death he was to suffer for our redemption, Isaiah and Zechariah have spoken of those matters fully and with certainty. The glory of his resurrection and the nature of his Kingdom, and the grace of the salvation he was to bring to his people – these things were fully treated by Isaiah, Jeremiah, and Zechariah.
Such promises, declared and testified to by these holy men who were filled with the Spirit of God, have been the comfort and consolation of the children and elect of God, who have nourished, supported, and sustained their hope in these promises, waiting upon the will of the Lord to show forth what he had promised. Many kings and prophets among them have desired greatly to see its accomplishment, never ceasing all the while to understand, in their hearts and spirits by faith, the things they could not see with their eyes. And, God has confirmed his people in every possible way during their long waiting for the great Messiah, by providing them with his written law, containing numerous ceremonies, purifications, and sacrifices, which were but the figures and shadows of the great blessings to come with Christ, who alone was the embodiment and truth of them. For the law was incapable of bringing anyone to perfection; it only presented Christ, and like a teacher spoke of and led to him, who was, as was said by Saint Paul, the end and fulfillment of the law.
Patterns of Christ:
Similarly, many times and in various seasons, God sent his people kings, princes, and captains, to deliver them from the power of their enemies, to govern them in peace, to recover their losses, to give them flourishing reigns, and by great prowess to make them renowned among all the other peoples. He did all this to give them a foretaste of the great miracles they were to receive from this great Messiah, who was to be endowed with all the power and might of the Kingdom of God.
But when the fullness of time had come and the period foreordained by God was ended, this great Messiah, so promised and so awaited, came; he was perfect, and accomplished all that was necessary to redeem us and save us. He was given not only to the Israelites, but to all men, of every people and every land, to the end that by him human nature might be reconciled to God. This is what is stated plainly in the next book (the New Testament), and set forth there openly. This book we have translated as faithfully as we were able according to the truth and the style of the Greek language, to enable all Christians, men and women, who know the French language, to understand and acknowledge the law they ought to obey and the faith they ought to follow.
Oh, and this bit is just awesome:
Without the gospel everything is useless and vain; without the gospel we are not Christians; without the gospel all riches is poverty, all wisdom, folly before God; strength is weakness, and all the justice of man is under the condemnation of God. But by the knowledge of the gospel we are made children of God, brothers of Jesus Christ, fellow townsmen with the saints, citizens of the Kingdom of Heaven, heirs of God with Jesus Christ, by whom the poor are made rich, the weak strong, the fools wise, the sinners justified, the desolate comforted, the doubting sure, and slaves free. The gospel is the Word of life and truth. It is the power of God for the salvation of all those who believe; and the key to the knowledge of God, which opens the door of the Kingdom of Heaven to the faithful by releasing them from sins, and closes it to the unbelievers, binding them in their sins. Blessed are all they who hear the gospel and keep it; for in this way they show that they are children of God. Woe to those who will not hear it and follow it; because they are children of the devil.