Answered by: Alimah Habiba Akhtar
Is the sunnah of Khilal of fingers/toes fulfilled by placing them under running water to the extent the skin in between becomes wet?
In the name of Allah, the Most Gracious, the Most Merciful
The act of Khilal is intertwining the fingers between the fingers or toes and rubbing. This is a Sunnah act that is done after the water has reached that area. (1)
Thus, Khilal is the follow up to washing the arms/hand and feet which are required for wudhu and the act that you refer to of wetting the area between the fingers or toes is washing and not Khilal. The water must reach those areas anyways as water must reach the entire limb therefore just the washing will not account for Khilal but the act of using the fingers to rub between the fingers and toes will be considered Khilal and this must be done to fulfil the Sunnah act of Khilal.
Only Allah knows best
Written by Alimah Habiba Akhtar
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
( و ) تخليل ( الأصابع ) اليدين بالتشبيك والرجلين بخنصر يده اليسرى بادئا بخنصر رجله اليمنى وهذا بعد دخول الماء خلالها
(Raddul Mukhtar, Vol 1, Page 238, Darul Ilm Kutub)