Bob Weir spoke about the writing of Eternity, during studio sessions for Rob Wasserman's Trios album, for in an interview for Guitar Player magazine in 1993;

I had this chord progression and melody that I wanted to run by Willie to see if he liked it .... he did, so he started dashing off words. He wanted me to run a certain section by him again and stuff like that, and we started working on a bridge. Then he dashes off this sheet of lyrics and hands it to me. Now I'm really stoked to be working with the legendary Willie Dixon and I'm prepared for just about anything.

He hands these lyrics to me and I'm reading through them. And they seem, you know, awfully simplistic. Like there wasn't a whole lot to them....

....Now he wants me to read through it and sing the melody I have and see if they fit. And so I started singing through these simplistic lyrics, and that simplicity takes on a whole other direction.

By the time I had sung through them, it's like my head is suddenly eons wide. I can hear what's happening just sort of echoing around in there and I'm astounded by the simple grace of what he has just presented to me. I'm sitting there with my mouth open literally, and Willie's laughing. He's just sitting there laughing, saying, 'Now you see it. Now you see it. That's the wisdom of the blues.'