Mishkat al-Masabih 4 Prayer كتاب الصلاة 312

وَعَنْ أَنَسٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «اعْتَدِلُوا فِي السُّجُودِ وَلَا يَبْسُطْ أَحَدُكُمْ ذِرَاعَيْهِ انْبِسَاطَ الْكَلْبِ»

Anas reported God’s Messenger as saying, “Adopt a moderate position when prostrating yourselves, and see that none of you stretches out his forearms [on the ground] like a dog.” (Bukhari and Muslim.)