Shaykh Muhammad Ibn Hizaam was asked:
“What is the ruling of wiping upon the sandals?”
“(النعلان) refers to that which is under the two ankles (i.e. sandals, slippers). The majority of the scholars are of the view that it is not allowed to wipe over the sandals because an authentic narration has not been affirmed in regards to it from the Prophet (ﷺ).
As for the narration of al-Mugheerah (may Allah be pleased with him) reported by At-Tirmidhi and Abu Dawood that the Prophet (ﷺ) wiped over the leather socks and sandals, then it is a weak narration. Thus, the sandals are not wiped over due to there not being an authentic narration in regards to that.
As for the narration of Ibn Umar (may Allah be pleased with him) reported by al-Bazzar that he wiped over the two sandals, then it is a narration with a hidden defect. As well that which is correct in regards to the wording of the narration is that he used to wash his feet in his sandals as Imam al-Bukhari (may Allah have mercy upon him) indicated. As for if the sandals have straps, then it is more befitting that they are not wiped over for they do not cover the foot at all.
The ones which have some laces, then they do not cover the foot. As for if it covers the top of the foot while it is lower than the ankles, then this is problematic because it resembles the leather socks.
With that being said, it is safer not to wipe over it since there has not come any affirmed texts in regards to it. The leather sock (الخف) is that which is above the two ankles. The evidence is the narration in regards to the one in the state of Ihraam. The Prophet (ﷺ) said, after prohibiting the one in the state of Ihraam from wearing the two leather socks,
‘he should not wear the two leather socks except if one has no sandals in which case he should cut short the leather socks below the ankles.’
Thus, the scholars used that as evidence that that which is under the ankles is not wiped over, and it is possible that he wipes over the socks under the sandals, or he washes his feet in the sandals as Ibn Umar (may Allah be pleased with him) did. The narrations reported in regards to wiping over the sandals have all been declared to have hidden defects. As well as the narration of Ali Ibn Abi Taalib (may Allah be pleased with him) reported by at-Tahaawi. It has been declared to have a hidden defect as well.”
“Some socks don’t keep the foot warm if the weather gets extremely cold, but if there is a little cold it keeps them warm. Is it allowed to wipe over it?”
“Yes, he wipes over them as long as they are suitable for keeping the feet warm.”
“As for the one who wipes over his leather socks, does he do so using new water or with the water remaining from his hand sufficient to use?”
“What is better is that it be done with new water for perhaps the water has disappeared when he wiped his head. If some water remains on his hand and he wipes with it, then it counts. If water remains and it goes from his hand to the sock then it is counted, but if it does not, then it does not count” End translation.
Majid Jawed Al-Afghanee