Sunan an-Nasa'i, Book 11, Hadith 153 (In-Book) ⓘ
It was narrated from Anas that the Messenger of Allah said: "Be moderate in bowing and prostration, and do not rest your forearms along the ground like a dog."
أَخْبَرَنَا سُوَيْدُ بْنُ نَصْرٍ، قَالَ أَنْبَأَنَا عَبْدُ اللَّهِ بْنُ الْمُبَارَكِ، عَنْ سَعِيدِ بْنِ أَبِي عَرُوبَةَ، وَحَمَّادِ بْنِ سَلَمَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " اعْتَدِلُوا فِي الرُّكُوعِ وَالسُّجُودِ وَلاَ يَبْسُطْ أَحَدُكُمْ ذِرَاعَيْهِ كَالْكَلْبِ " .
also referenced under: Hadith 1028 (Reference) & Volume 2, Book 11, Hadith 1029 (DarusSalam)