How we cite our quotes: (Part.Chapter.Paragraph)
Quote #1
"Your Daddy beats you," she said, "because he loves you."
Elizabeth is defending Gabriel against Roy's accusations, and we really can't tell whether she believes her own story. If she does, she must think that Gabriel's strictness and violence against his family are a (misguided?) attempt to keep them all safe; otherwise, she's just trying to make her kids feel better because they're in a terrible but inescapable situation.
Quote #2
Roy got stabbed with a knife. Whatever this meant, it was sure that his father would be at his worst tonight. (1.1.136)
And voila, from one act of violence we get another. See how it spreads? As soon as John finds out about his brother's accident he knows that someone is going to get a beating. Even though the perpetrators are nowhere to be found, Gabriel's anger is going to have to find somewhere to land, and it will be on his family.
Quote #3
Time would darken the half-moon wound into Roy's dark skin, but nothing would bring together again the so violently divided eyebrow. This crazy lift, this question, would remain with him forever, and emphasize forever something mocking and sinister in Roy's face. (1.1.164)
Roy has been stabbed in the forehead, and the scar it leaves is an act of violence all on its own. By marking Roy for life, the wound is showing everyone that he's a violent guy, the kind of guy who gets into knife fights. That "mocking and sinister" look will probably get him into even more trouble later on, in a vicious cycle.