Q's # 2204 says:
Sep 17 2018 19:54:01 (EST)
PANIC IN DC
SESSIONS CLAS LETTER TO SC JUSTICES 1&2 RE: RECUSAL,
UNRECUSAL, AND CLARITY RE: CONFLICTS BASED ON
UNCLASSIFIED MATERIAL [TODAY]
Since the letter is classified, it appears that, for now, we will have to take Q's word for this.
Rush Limbaugh wrote a piece on his web site on July 27, 2017 quoting ex-fed prosecutor Andy McCarthy on how Sessions could go about it.
Found an old Q post from Jan 21, 2018 (543) that mentions the Sessions memo and it's relevance:
Thank you for your input. Gonna be one heck of a Q proof when it all falls into place.