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).
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.
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.