"When the Prophet ﷺ would sit in the prayer, he would place his left foot horizontally - so much so that the upper-part of his foot became black."
كَانَ النَّبِيُّ ﷺ إِذَا جَلَسَ فِي الصَّلاَةِ افْتَرَشَ رِجْلَهُ الْيُسْرَى حَتَّى اسْوَدَّ ظَهْرُ قَدَمِهِ