What does Genesis 40:8 mean?

Pharaoh's former cupbearer and baker sit languishing in prison for some untold crime (Genesis 40:1–3). Their caretaker is also a prisoner, but one unfairly jailed for a false charge (Genesis 39:11–15). Joseph has proven his use to the jailer and been given considerable responsibilities in the prison (Genesis 39:21–23). That includes some authority over these two men (Genesis 40:4). For all three men, their futures seem bleak. Recently, the baker and cupbearer are troubled for another reason. On the same night, they both had separate, deeply impactful dreams (Genesis 40:5–7).

The Egyptians held dreams to be very important, in general. They believed dreams allowed for contact with the dead and with the gods. Some Egyptians specialized in claiming to interpret significant-seeming dreams for people. The cupbearer and the baker cannot understand their visions, but they know they are important (Genesis 40:5–6). They likely wished they could talk to one of those dream specialists.

Joseph dismisses that superstition with a single statement: interpretations belong to God. Joseph saw his God as the revealer. Dream specialists were not required for someone who was in communication with the one, true God, as Joseph was. He asked the men to tell him the dreams, implying that God would give him the revelation and he would tell it to them. That's exactly what happens (Genesis 40:9, 16).