We will have three answers to that question. The first one is because his character wasn't prepared to be lifted up over the whole land of Egypt yet. The Eternal had a plan to save many people and His way of treating Yosef worked accordingly with that plan. Suffering and trouble produce a beautiful result in the character of a righteous man when he knows how to cope with it correctly. The righteous one learns obedience through suffering. The one who wants to flee from suffering doesn't know the way of the righteous ones.

The second reason is that Yosef was put in prison because that was the path the Eternal had set for him to be lifted up. If he hadn't been in jail he wouldn't have met the chief cup bearer who later was the key person, who helped him out of there and took him before Pharaoh. The path to success goes through distress.

The third reason is that Yosef had to prophetically reflect what would happen with the Messiah son of Yosef. There is no clearer and more detailed narration in the Scriptures about the suffering, death, resurrection and glorification of the Messiah than the narration of Yosef's life. Jail is a prophetic symbol of the death of the Messiah. Due to false accusations he was delivered to die in order to then be lifted up to the highest position in all creation. So, Yosef lived on a smaller scale, what Messiah Yeshua would live further on to become the great saviour of Israel and the world.

So, even if Yosef was in jail, he didn't lose hope of getting out. His eyes were fixed on the promises of the Eternal; with His help he could interpret his own dreams correctly and he knew they would be fulfilled.

That's why he cheered up in the middle of misery and did what he had always done; he took care of others and served them with all that was at hand.

Love doesn't seek its own good, but the others'. Love surrenders to common welfare. Love seeks solutions where there are none. Love believes in a good God who can help the needy in difficult times.

Yosef trusted that the Eternal would give him revelation to interpret the dreams of the officers under his responsibility. And quite true, in the moment when they told their dreams, he received, through prophetic revelation, the right interpretation to both cases.

Here we can see another ingredient in Yosef's life: faith.

Faith means faithfulness and trust. Yosef didn't trust or had too much faith in himself or in his own abilities, but in the Almighty who was with him at all times. He knew that The Eternal wouldn't let him down and his trust was honoured by heaven.

However, when the chief cup bearer took his previous position again after three days, he forgot Yosef. Why? Because Yosef spoke ill of his brothers and wanted to cunningly take advantage of that contact to get out of jail. That's why he had to spend another two years there until that part of his character was polished and prepared for the mission he was born to carry out.