It started with the words but the words came with a melody in my head so I was able to bang out the laid back bluesy riff that came with it. However, that was the chorus. The verse seemed (seems) to have a rhythm before I have real words but I have a sense of the vocal melody.
Since I've really just started recording in ernest, I'll see how it all pans out (much less my singing...).
Lyrics without a sense of melody, I think, are hard to work with.