مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 4417
Clothing
Sandals - Section 2
وَعَن ابنِ عبَّاسٍ قَالَ: مِنَ السُّنَّةِ إِذَا جَلَسَ الرَّجُلُ أَنْ يَخْلَعَ نَعْلَيْهِ فَيَضَعَهُمَا بِجَنْبِهِ. رَوَاهُ أَبُو دَاوُدَ
Ibn Abbas said it is part of the sunna that when a man sits down he should take off his sandals and place them at his side. Abu Dawud transmitted it.
Mishkat al-Masabih, 4417لم تتمّ دراسته (الألباني)