Indeed. What I love about this track, besides the mantra, are the layers of rhythm that make up the groove. This is Funk.
Fred Wesley relies on rhythm and syncopation. In this solo, he uses "the hiccup" technique, as I call it, to accent the offbeat rhythms (one-AND-Ah). When you have a large band, you have to be able to set yourself apart from everything that's going on underneath your solo. Playing against this bed of rhythm is a good way to stand out, and Fred is a master of this style of playing.
A couple interesting observations: Most of the groove takes place in Eb minor. During the bridge, it jumps to the key of A minor, where there's an organ solo. I assume this is Brown on the keys and that he forced the band to go to A minor (only the white keys). Oddly enough, Eb minor pentatonic only uses the black keys.
Also, Fred's solo appears to fade out around the 4:07 mark. My first thought was that this is the studio crossfade between Parts 1 & 2. However, after watching some YouTube videos of the original 45 press, Part 1 appears to end before Fred's solo. So my second thought was that maybe Fred's chops blew out during the solo, and they just fixed it in the mix by turning off his mic. When the horns come back in, you can hear that the trombone sounds a little shot. Who knows?
Speaking of YouTube videos, here's a great interview with Fred Wesley.
Recommended Reading: Hit Me Fred: Recollections of a Sideman by Fred Wesley Jr. Published by Duke University Press.