Assalaamu alaykum. If someone says, "Damn it," whether deliberate or not, to an object, does it become haram for him to keep it in possession? Also, I wear a robe that covers until my thigh and a long loose skirt when I pray at home. If someone were to peek from exactly below the robe (which of course does not happen), my ʻAwrah (what should be covered of the body) would be seen. Is my prayer valid?

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

It is not true that if someone curses an object it becomes haraam (unlawful) for him to own it. It was reported that a woman cursed her she-camel. The Prophet, sallallaahu ‘alayhi wa sallam, said regarding this woman's she-camel, "Unload it and leave it, for it is cursed." This hadeeth does not indicate that it is impermissible to benefit of the object whose owner has cursed. An-Nawawi wrote, "What is meant is forbiddance to accompany him with that she-camel on the road. As for selling it, slaughtering it, or riding it without accompanying him () and any other actions that were permissible before this incidence (the cursing), they continue to be permissible."

If the clothes that you are wearing while praying cover your ʻAwrah, namely the whole body except the face and hands, your prayer is valid. Even if someone happened to peek from below and saw your ʻAwrah, this does not invalidate your prayer. An-Nawawi wrote, "Our companions held that it is a condition to cover the ʻAwrah from above and the sides; it is not a condition to cover it from below the bottom and the waist sheet; even if the garment has a loose bottom and the person prays at the edge of a roof and his ʻAwrah is seen by someone looking at him from below, his prayer is valid." [Al-Majmooʻ]

Allah knows best.