The Messenger of Allah ﷺ said: Observe moderation in prostration, and let none of you stretch out his forearms (on the ground) like a dog.  

قَالَ رَسُولُ اللَّهِ ﷺ اعْتَدِلُوا فِي السُّجُودِ وَلاَ يَبْسُطْ أَحَدُكُمْ ذِرَاعَيْهِ انْبِسَاطَ الْكَلْبِ  

" None of you should stretch out his forearms like the stretching out of a dog."  

حَدَّثَنَا شُعْبَةُ بِهَذَا الإِسْنَادِ وَفِي حَدِيثِ ابْنِ جَعْفَرٍ وَلاَ يَتَبَسَّطْ أَحَدُكُمْ ذِرَاعَيْهِ انْبِسَاطَ الْكَلْبِ  

The Messenger of Allah ﷺ said. When you prostrate yourself, place the palms of your hands on the ground and raise your elbows.  

قَالَ رَسُولُ اللَّهِ ﷺ إِذَا سَجَدْتَ فَضَعْ كَفَّيْكَ وَارْفَعْ مِرْفَقَيْكَ