Arrepentimiento translates to "repentance" or "regret." It's a profound and less common word in everyday Spanish, making it stand out in song lyrics.
In Mon Laferte's song, the word appears in a powerful, almost sermon-like declaration: "Puede ser transformado solo por el arrepentimiento!" (Can be transformed only by repentance!). This highlights a central theme of redemption and moral reflection, giving the word significant weight and making it highly memorable.
Mon Laferte names this song after a Bible verse about the death penalty for cursing your parents, then spends four minutes aiming it at a lover instead. She opens with "Dios, ya sabe tu nombre y yo no quiero / Que cuando mires al cielo veas al diablo" ("God already knows your name, and I don't want you to see the devil when you look at the sky"). She has done something, God already knows about it, and the part she dreads is what it has done to the other person's view of heaven. The chorus barely bothers with a sentence: "Corazón maldito, mala" ("Cursed heart, wicked one"), repeated until it stops sounding like an insult and starts sounding like a name she has agreed to answer to.
Two and a half minutes in, a preacher bursts through the mix shouting the verse itself: "¡El que maldiga a su padre o a su madre morirá!" ("Whoever curses his father or his mother shall die!"), then "¡Porque naciste en pecado!" ("Because you were born in sin!"). It is a lot, and it is supposed to be. The line that actually lands, though, is the quiet one earlier on: "No sabes cuánto me duele hacerte daño / Yo he sufrido mucho más que tú" ("You don't know how much it hurts me to hurt you / I have suffered much more than you"), which is the oldest trick there is from the person holding the knife. She follows it by asking for "Déjame sufrir en paz, apaga la luz" ("Let me suffer in peace, turn off the light"). Her last word in the song is "Mala" ("Wicked one").