It was narrated from Ibn ‘Umar that the Messenger of Allah ﷺ said:
“Whoever does not have sandals let him wear leather socks, and let him cut them to below the ankle.”

حَدَّثَنَا أَبُو مُصْعَبٍ، حَدَّثَنَا مَالِكُ بْنُ أَنَسٍ، عَنْ نَافِعٍ، وَعَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ " مَنْ لَمْ يَجِدْ نَعْلَيْنِ فَلْيَلْبَسْ خُفَّيْنِ وَلْيَقْطَعْهُمَا أَسْفَلَ مِنَ الْكَعْبَيْنِ " .