I was reading a children book called "흰곰한테 시집갈게요" when I came across this passage:
깜짝 놀란 농부가 비쭉 문을 열고 나가자, 웬 흰곰이 넙죽 인사를 하는 거야.
순간 농부는 덜컥 겁이 났지만, 흰곰이 순해 보여 안심하고 물었어.
“대체 무슨 일이냐? 우릴 다 찾아오다니!”
“막내딸을 저에게 주세요. 그럼 당장 큰 부자가 되게 해 드릴게요.” 그 말에 농부는 귀가 번쩍 뜨였지만 곧 큰 눈을 끔벅이며 말했어.
From my understanding, "그 말에" indicates that what follows after is the farmer's reaction to the bear's words. But I don't really get what "귀가 번쩍 뜨였지만" means, because my translation of it would be "opened his ears wide, but" (?), but that doesn't sound right to me. Also, if my research is correct, 이며 here works similarly to 고, but I'm not really sure what the 말했어 that follows after it means and how those two words relate to each other. Overall, I would be really grateful if someone could break down this sentence grammatically for me.