Jeremiah 11:11
King James Version
11 Therefore thus saith the Lord, Behold, I will bring evil upon them, which they shall not be able to escape; and though they shall cry unto me, I will not hearken unto them.
https://www.esquire.com/entertainment/movies/a26929824/jeremiah-11-11-us-meaning-jordan-peele-theory-spoilers-explained/
Early in Jordan Peele's Us, young Adelaide sees a man holding a sign that says "Jeremiah 11:11" on a ripped piece of cardboard just before she runs into her own young doppelgänger. The bible passage then proceeds to become a recurring motif throughout the movie. We see it again when Gabe is watching baseball, the announcer says “we’re tied at 11:11.” Then, Jason points out that the clock in Adelaide's bedroom reads 11:11 p.m. We also subtly see 11:11 represented in a Black Flag t-shirt worn by one of the Tyler twins in the form of four blocks.
When Adelaide returns to the Santa Cruz beach as an adult, she sees the same man who held the cardboard sign dead and being pushed into an ambulance. As Peele has explained about Us, "There’s a double meaning to everything…This movie’s about duality.” That type of duality is represented visually with the mirrored image of 11:11. But, beyond that, the idea works thematically with Us as well.
So, what does this specific bible verse mean? In the King James Bible, the verse reads:
"Therefore thus saith the Lord, Behold, I will bring evil upon them, which they shall not be able to escape; and though they shall cry unto me, I will not hearken unto them."