The Spanish libra (“pound”) comes from the same Latin word word, libra, meaning, “pound; balance.”
From that root, we get the English: equilibrium (literally, an “equal balance”) as well as deliberate, which literally means “to weigh carefully” (with the de- emphasis).
In Spanish, you weigh literally — but in English, metaphorically.
You can see the l‑b-r root in all of the words.