The priest in Dr. Rush's vision is played by Ron Halder. Halder played Cronus in three episodes of Stargate SG-1 (1997) and reprised the role for Stargate: Continuum (2008). He also voiced a character in one episode of the non-cannon Stargate Infinity (2002).
This is the second time the number "42" from the Hitchhikers Guide to the Galaxy is referenced in the Stargate franchise. The first time is in Stargate: Atlantis (2004)'s Quarantine (2008). It is the last two numbers in McKay's password.
In Dr. Rush's dream sequence while in the chair, his wife's friend Constance, played by Suleka Mathew, also played in two episodes of Stargate SG-1 (1997)'s Season 5 as the Goa'uld Kali.