(13) باب الصَّفِّ بَيْنَ الْقَدَمَيْنِ فِي الصَّلاَةِ
It was narrated from Abu Ubaidah that:
Abdullah saw a man who was praying with his feet together. He said: "He is going against the Sunnah; if he shifted his weight from one to the other that would be better."
Reference: Sunan an-Nasa'i 892
In-book reference: Book 11, Hadith 17
English translation: Vol. 2, Book 11, Hadith 893