The prayer that Gabriel recites at Siddiq's funeral - "We created you from it, and returned you to it. And from it, we will raise you a second time" - is from the Quran (20:55). Siddiq's character was Muslim, and when he first met Carl he also quoted the Quran.
The book Judith is reading has the same title as the episode.
Juan Javier Cardenas and Kevin Carroll previously appeared together on the first season of Snowfall (2017).