Genesis 15:12 reads “And when the sun was going down, a deep sleep fell upon Abram; and, lo, an horror of great darkness fell upon him.” And it is in this state, that the Lord speaks to Abram. The Lord tells him to be assured that though his seed would be a stranger and slaves in a land that is not their own (for four hundred years), The Lord will judge the nation who will be their master. His seed will be come out of the land of their captivity with great substance (possessions) and he himself will pass away in peace. Then The Lord makes a covenant to him after accepting Abram’s sacrifice that he will give to Abram’s seed the land and lists out the region that would be Abram’s property. 

While, on the surface, it may seem that a word of sojourning and slavery is not exactly what Abram would want to hear when he was engulfed with a horrifying darkness, closer scrutiny of what the Lord was promising Abram reveals certain hidden treasures from the Scripture, which is actually quite amazing. 

First, this is a promise of progeny. Abram had no child of his own at this time, and yet the Lord promises to Abram a seed and a nation from him. 
Second, this is a promise of protection. The Lord promises to be the judge of the nations that enslaves the seed of Abram.
Third, this is a promise of provision. The Lord promises to bring Abram’s children, out of their land of slavery with great provisions (substance) proving to Abram that he indeed is Jehovah-Jireh.
Fourth, this is a promise of peace. While Abram was a in a state of fear (as a dreadful darkness loomed around him), The Lord promises him Abram will go to his grave in a good old age in peace.
Finally,  this is a promise of property. The Lord lists out the land of 10 nations (Kenite, Kenizzite, Kadmonites, Hittites, Perizzites, Rephaims, Amorites, Canaanites, Girgashites and Jebusites) as the lands that he will give to Abram.

Points to ponder:
When it seems like you are in a dark place and all that surrounds you just darkness (great darkness), listen intently to what The Lord is promising you … it may be a promise of progeny to the one who is barren, a promise of protection to the one who is defensless, a promise of great provision to the one who is needy, a promise of peace to those who are unrestful, and a promise of property to the one who has no possessions … or it may be all of the above. What is The Lord promising to you today (amidst great darkness that may be surrounding you)?

Genesis 15:12-21 (KJV)
12 And when the sun was going down, a deep sleep fell upon Abram; and, lo, an horror of great darkness fell upon him.
13 And he said unto Abram, Know of a surety that thy seed shall be a stranger in a land that is not theirs, and shall serve them; and they shall afflict them four hundred years;
14 And also that nation, whom they shall serve, will I judge: and afterward shall they come out with great substance.
15 And thou shalt go to thy fathers in peace; thou shalt be buried in a good old age.
16 But in the fourth generation they shall come hither again: for the iniquity of the Amorites is not yet full.
17 And it came to pass, that, when the sun went down, and it was dark, behold a smoking furnace, and a burning lamp that passed between those pieces.
18 In the same day the Lord made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates:
19 The Kenites, and the Kenizzites, and the Kadmonites,
20 And the Hittites, and the Perizzites, and the Rephaims,
21 And the Amorites, and the Canaanites, and the Girgashites, and the Jebusites.