And I have promised to bring you up out of your misery in Egypt into the land of the Canaanites, Hittites, Amorites, Perizzites, Hivites and Jebusites--a land flowing with milk and honey. (Exodus 3:17)
The Israelites were in a miserable condition in Egypt. 430 years of slavery. Pain, injury and shame were their wages for working hard. And God decided to end it all.
Long before all these years of slavery, God had spoken to Abraham regarding this bondage and the redemption. He said,
"Know for certain that your descendants will be strangers in a country not their own, and they will be enslaved and mistreated four hundred years. But I will punish the nation they serve as slaves, and afterward they will come out with great possessions." (Genesis 15:13, 14)
And it happened exactly as God said.
What God promises, he brings about at his appointed time and no one can stop him. The
Your promises have been thoroughly tested, and your servant loves them.(Psalms 119:140)
Again in Psalms 145, we read,
Your kingdom is an everlasting kingdom, and your dominion endures through all generations. The LORD is faithful to all his promises and loving toward all he has made. (v13)
Even in your life, If God has promised you something, he will bring it to fulfillment, because the Bible says,
For no matter how many promises God has made, they are "Yes" in Christ. And so through him the "Amen" is spoken by us to the glory of God. (2 Corinthians 1:20)