Archer is wearing the Poovey Farms Racing hat from a previous episode.
Randy's Bible quote, Genesis 38:8 says, "And Judah said unto Onan, Go in unto your brother's wife, and marry her, and raise up descendants to your brother."
The Bible verse Randy is referring to, Genesis 38:8, reads: "In view of that Judah said to Onan: 'Have relations with your brother's wife and perform brother-in-law marriage with her and raise up offspring for your brother.'" Out of context this sounds like the Bible is condoning polygamy and adultery, but as Ray points out, that is not what this verse means. In the preceding verses it is revealed that Er, Onan's older brother, was put to death for being "wicked in God's eyes" and Er's wife had several children at the time, and as Onan wasn't married yet, Judah was instructing him to marry his brother's widow and raise his brother's children as his own.
Ray's brother is actually called Randy, the alias that Archer invariably chooses for himself when going undercover.
Pam's toilet graffiti is dairy-farm-themed because it has been established that she grew up on a dairy farm.