They bruised his feet with shackles, his neck was put in irons, till what he foretold came to pass, till the word of the LORD proved him true (Psalm 105:18,19).
God spoke to Joseph as a young boy through a dream and vision regarding his future. He could not understand its complete meaning at the time, but he knew it had great significance. Joseph knew God had a destiny for his life. However, the proving out of that word from God was filled with thirteen years of waiting, rejection, pain, sorrow and, no doubt, questioning God's faithfulness.
His life was all but a life of influence and impact as a prisoner and slave. No doubt he wondered whether that dream was simply some vain imagination. David must have felt the same when he was anointed king over Israel as a young man only to spend years of fleeing from the sword of King Saul. God's preparation for greatness in His Kingdom is often filled with difficult preparation. God is more concerned about developing the inner life of his servant. That inner life can only be prepared by removing all "self"-confidence and replacing it with "God"-confidence. God-confidence is only developed in the furnace of life.
Is the Lord proving His word in your life? Perhaps He is using circumstances and events to move you into a place of patient waiting as He puts you in the place He desires for you. This is the place where the foundations of your soul mature. Let Him prove your faith.