All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
According to the authentic Ahaadeeth, the Prophet, sallallaahu ‘alayhi wa sallam, stated that it is permissible for the resident to wipe over the Khuff (leather socks) and socks for a day and a night and for the traveler for three days and nights. We have explained this in Fataawa 82001 and 87359.
With regard to nail polish, if it prevents water from reaching the nails, then ablution is invalid. The majority of scholars of jurisprudence, including the four Imaams and others, stated that one must remove whatever prevents water from reaching the organs that must be washed in ablution. They exempted the splint, since it is a necessity. They also exempted the Khuff and socks because the Prophet, sallallaahu ‘alayhi wa sallam, allowed wiping over them. Of course, the need for wearing Khuff and socks is not like the need for applying nail polish.
Moreover, the Khuff and socks cover the whole of the feet, contrary to nail polish. Hence, many scholars are of the view that if the Khuff has holes in such a way that reveals part of the feet, then wiping over it is invalid because, in this case, the same organ will be washed and wiped over at the same time, i.e. the revealed part will be washed and the covered part will be wiped over.