Whether the Order of the Limbs in the Ablution Must Be Kept
Must the limbs be washed in the order given in the verse, or is the ablution valid if some are washed before others?
Keeping the order of the limbs is an emphasised sunnah, not an obligation: if one reverses it — washing the feet before the face — the ablution is valid, though disliked.
Keeping the order among the obligatory acts of the ablution is a sunnah: whoever reverses it, his ablution is valid; it is sunnah for him to repeat the reversed act alone if the interval has grown long enough for drying, and otherwise to repeat it together with what follows it.
The order is one of the obligations of the ablution and it is not valid without it, since the verse sets it out in sequence; whoever washes a limb out of its place, that washing does not count.
The order is one of the obligations of the ablution and it is not valid without it, on the strength of his saying ﷺ: “Begin with what Allah began with”, related by al-Nasāʾī; whoever departs from it, his ablution is void.