What is the ruling on exposing the foot up to the calf while wearing the Khuff (leather stocking) regarding Wudu (ablution)?
Chapter on Wiping over the Khuffayn (Leather Socks)
Al-Mughni
Book of Purification
Primary text
If a person removes their foot up to the calf (sāq al-khuff) from the Khuff, it is considered as if the Khuff has been removed entirely. This position is held by Ishaq and the Companions of Ray' (Ahl al-Ra'y). The justification is that the stability (istiqrār) of the foot within the Khuff is a condition for the permissibility of wiping over it. Evidence for this is that if one puts on the Khuff and then invalidates their Wudu before the foot settles properly, wiping is not permitted. Therefore, when this stability is disrupted, the condition for the permissibility of wiping ceases, thus nullifying the wipe, similar to the nullification of covering itself.
Supporting text
Al-Shafi'i holds that ablution is not necessitated because the foot has not become fully uncovered. Another narration is reported from Ahmad, transmitted by Abu Al-Khattab in 'Ru'us Al-Masa'il,' which aligns with the view that ablution is not necessitated. If the foot is removed only to a point less than the calf, the wipe remains valid because the foot has not entirely left its stable position.