The gods' power rests on their control of the forests. They employ this man, Humbaba, to run the operation. Humbaba is the key!
The whole world fears Humbaba. If anything happens in the forest he knows, and if anybody touches the gods' trees they die! But if we defeat Humbaba, then we control the forests, and the gods have to do things our way! We will be as the gods! We will be legends forever!
Enkidu is not convinced. He says he knows Humbaba. Humbaba is known as "the battering ram" for how he smashes all enemies. Should we stop and think? But maybe that just gives him more time to prepare. Maybe we should march to his palace right now, before he knows what hit him? Or do something else?