Exodus chapter 12. 

God declared in the past He would deliver the Israelites from the Egyptians. 430 years later and it finally happened. This is a reminder that when we ask God for his intervention and answer to our prayer that his timing is better than our timing. I think it is dangerous to expect God to answer immediately. In those days of waiting it is an opportunity to grow spiritually and develop in strength, character, integrity and see God work his power and work in the hearts of even other people. Gods answered prayers may come quickly but we can't expect him to work in our timing when his timing is best.