‘And he said to Abram, “Know for a guaranteed certainty that your seed will be a stranger in a land that is not their's, and will serve them, and they will afflict them, for four hundred years. And that nation whom they serve I will also judge. And afterwards they will come out with great substance. But you will go to your fathers in peace. You will be buried in a good old age. And in the fourth generation they will come here again. For the iniquity of the Amorites is not yet full”.'
Yahweh reveals to Abraham something of the future. Firstly that the certainty of him having seed comes out in that God can speak of their future. Secondly that their future will not be straightforward. They will be aliens and slaves in a foreign land. He has control of their destiny. But it stresses that their land will not be theirs for a long time to come. Thirdly there is the implication that this will be followed by them receiving a land of their own. Fourthly it brings out Yahweh's power as the One Who can alone determine the future of that foreign land as their Judge. He is not a local tribal god. Fifthly Abraham has the guarantee that it will not happen in his lifetime. Sixthly it brings out that God is a God Who acts as Judge only in the light of true moral necessity. His judgments are not arbitrary, but on a moral basis, and He will not punish or condemn any until it is necessary, and will judge according to deserts. Again there is the implication that all judgment is in His hands. He is over all. Other ‘gods' were arbitrary and limited in what they could do and rarely took morality into account. They were simply sinful super-humans.
This recognition of God's power and goodness may be obvious to us. In the time of Abraham it was very special revelation.
The Amorites here represent the inhabitants of the whole of Canaan and Transjordan. The depth of their iniquity is spoken of in Leviticus 18:24-27 where the full nature of their sexual abominations, resulting from their debased religion, are discreetly described. But it has not yet reached its pinnacle and therefore a period of waiting is necessary. Yahweh allots to nations their times and seasons (Daniel 2:21). Thus again does the writer remind us of the universal sovereignty of Yahweh.
The interchanging of the terms ‘Canaanites' and ‘Amorites' to describe the people of the land (although they are not necessarily precisely synonymous) is testified to in Egyptian texts where the inhabitants of the land can be called ‘Canaan' or ‘the land of Amurru'.
This is a time of prophetic revelation. Yahweh has previously promised the land to Abram but now he is made aware of what will result before its fulfilment. Before that time Abram's seed must be a stranger in a land that is not theirs. Already even now they were strangers in ‘a land that is not theirs', a land where there were many nations (a contrast with what is to be), but they will yet suffer under another single nation, who must therefore be a powerful nation, whom they will serve, and who will afflict them, and this condition will go on for four hundred years. But it is the service and not necessarily the affliction that will endure for this time.
Abram may well have thought of some great king coming in and subjugating the land, but the later reader aware of the final complete narrative will know what is meant
Yet when it happened there could be no complaint, for Israel could have returned from Egypt when things were going well, but they did not do so. They had this warning but they still did not do so. They preferred the land of delights and plenty to the land promised to them by God. Thus it was also through their own disobedience that they suffered. It is the result that is being prophesied, not what should be.
But the promises of Yahweh cannot be hindered by men's failure, or by great nations, and judgment will come on the nation which enslaves them and they will return to the land God promised them with great substance, just as Abram had himself come into the land with great substance, for God never does things by halves.
The number 400 is significant. Neither 3, 5 or 7 could be used for they would represent completeness, covenant connection and divine perfection. But four is certainly seen later as the number which signified the world and is the number of judgment. Four rivers flowing from Eden to encompass the known world outside the Garden (Genesis 2:10), 40 days of rain on the earth producing the flood (Genesis 7:12), 40 days still under judgment before release (Genesis 8:6), 400 hundred years signifying the decline of man (Genesis 11:12-17 - each with another significant number added on), four kings who were the first invaders of the land (14:9), four beasts who represent world empires (Daniel 2 and Daniel 7). Only four intensified could be used here. Thus it means a long period connected with world empire and judgment.
“But you will go to your fathers in peace, you will be buried in a good old age”. Abram is promised that while he is alive this will not happen. Until he dies there will be peace. To ‘go to one's fathers' was a stereotyped phrase meaning simply to die and be buried, for that is finally where one's ancestors were. ‘In a good old age' (compare Job 5:26). This was considered a special gift from God (compare Genesis 25:8). So Abram learns that the land will not be theirs in his day.
“In the fourth generation they will come here again”. Later a generation would be 40 years, but here it is a hundred years. Longevity was still remembered and enjoyed. Yet again the emphasis is on ‘four'. Thus the number may be symbolic and not necessarily to be thought of as needing to be applied too literally. Once God's judgment is ready for ‘the Amorites', the inhabitants of the land, then they will come back.
So finishes the prophetic ‘word of Yahweh' to Abram (Genesis 15:1). Now its fulfilment must be finally guaranteed.