"And fair women with large, beautiful eyes" (Hurun 'in), meaning: white-skinned, wide-eyed, the singular of which is 'ayna'.
Muhammad said: "And fair women with large, beautiful eyes" is in the nominative case, meaning: and they shall have fair women with large, beautiful eyes.
﴿وحور عين﴾ أَي: بيضٌ، عينٌ أَي: عِظَام الْعُيُون، الْوَاحِدَة مِنْهُنَّ عَيْنَاء.
وَقَالَ مُحَمَّد: ﴿وحور عين﴾ مَرْفوعٌ بِمَعْنى: ولهُمْ حورٌ عين.