Messenger of Allah said: "Be balanced in the prostration, and let one of you not spread his forearms (on the ground) in the Salat like the spreading of the dog."
سَمِعْتُ أَنَسًا يَقُولُ إِنَّ رَسُولَ اللَّهِ ﷺ قَالَ اعْتَدِلُوا فِي السُّجُودِ وَلاَ يَبْسُطَنَّ أَحَدُكُمْ ذِرَاعَيْهِ فِي الصَّلاَةِ بَسْطَ الْكَلْبِ