One should not put the forearms on the ground during prostrations

Sahih al-Bukhari · Book 10 · Hadith 822

حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، قَالَ حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، قَالَ حَدَّثَنَا شُعْبَةُ، قَالَ سَمِعْتُ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏"‏ اعْتَدِلُوا فِي السُّجُودِ، وَلاَ يَبْسُطْ أَحَدُكُمْ ذِرَاعَيْهِ انْبِسَاطَ الْكَلْبِ ‏"‏‏.‏

Narrated Anas bin Malik: 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."