Amazingly Embarrassing Parents: How Mrs. Oleson (with a generous dose of casual antisemitism) sees Percival's parents, even before they arrive for the first time. It gets worse when she gets into conflict with Percival's father on what religion their grandchild will follow.
Foreshadowing: Percival's mother commenting on her husband's health, including mentions to a recent heart attack, is Foreshadowing to when he's revealed to having passed in his sleep in the Season 8 premiere, causing Percival and Nellie to stay at New York and putting them on a bus.
Hates Being Nicknamed: Mr. Cohen doesn't take it lightly when he's called any variation of his name Benjamin. In the end, when Mrs. Oleson refers to their grandchildren Jennifer and Benjamin as "Jenny and Benny", he yells "BENJAMIN!" one last time, though he smiles afterward to show it's nothing personal this time.
Percival casually comments about his mother's opinion on the country townspeople as "savages", much to Mrs. Oleson's contempt.
Caroline greets Percival's father as "Mr. Dalton", unaware that his real name is Benjamin Cohen, and that his son's changing his name to hide his Jewish background is a source of great conflict between them.
Oblivious to Their Own Description: After meeting her son-in-law's jewish parents, Harriet keeps badmouthing them to Nels in bed, describing them with every antisemitic stereotype in the book, including "greedy, sneaky, big eaters" which Nels casually points out could just as well describe Harriet herself.
Surprise Multiple Birth: Nellie and Percival spend most of the episode thinking they're only expecting one baby. At the end, Nellie gives birth to twins, much to everyone's surprise.
Title Drop: Benjamin Cohen paraphrases the title quote "Come now, let us reason together" when he sees that his fights with Harriet have been alienating their children and tormenting his pregnant daughter-in-law, agreeing to having a peaceful conversation with the Olesons for once.
Unto Us a Son and Daughter Are Born: Nellie giving birth to twins, which she names Jennifer and Benjamin. It also forces compromise between Mrs. Oleson (who had wanted the baby raised as a Christian) and Mr. Cohen, who envisioned his grandchild being raised Jewish. Percival and Nellie had agreed to determine the child's religion based on its gender … and got the best of both worlds.
