The Prophet ﷺ said, "Be straight in the prostrations and none of you should put his forearms on the ground (in the prostration) like a dog." (Using translation from Bukhārī 822)
"اعتدلِوا في السُّجودِ، ولا يبْسُطْ أحدُكُمْ ذِراعيه انْبِساطَ الكلْبِ".