The Prophet of Allah, peace and blessings be upon him, said, "Maintain a balanced posture in prostration, and let none of you spread out his forearms on the ground like a dog."
حدثنا ابن أبي عدي وعبد الوهاب الخفاف عن حميد عن قتادة
أن نبي الله عليه الصلاة والسلام قال اعتدلوا في السجود ولا يفترش أحدكم ذراعيه كالكلب
Its chain of transmission is sahih. Bukhari related it, 1/141, in the chapters on the times of prayer, on the one who prays confiding in his Lord, and Muslim, in the book of prayer, on moderation in sujud, 1/355, no. 493, and Nasai, in the book of tatbiq, on moderation in sujud, 2/214, no. 1110, and Tirmidhi, in the book of prayer, on what has been said about moderation in sujud, 2/66, no. 276, from Jabir, and he said, hasan sahih, and Abu Dawud, in the book of prayer, on the description of sujud, 1/236, no. 897, and Ibn Majah, in the book of establishing prayer, on moderation in sujud, 1/288, no. 892, from Anas.