Be moderate in prostration, and let none of you spread his forearms on the ground like a dog. [Sahih/Authentic] - [Al-Bukhari and Muslim]
"«اعْتَدِلُوا في السجود، ولا يَبْسُطْ أحدكم ذِرَاعَيْهِ انْبِسَاطَ الكلب». [صحيح. - متفق عليه.]
