Anas reported the Messenger of Allah(ﷺ) as saying; Adopt a moderate position when prostrating yourselves, and see that none of you stretches out his forearms(on the ground) like a dog.
Sunan Abi Dawud Book 2, Hadith 507
← Previous Hadith Al-Bara' described to us (the nature of prostration). He placed his hands (palms), reclined on his knees, and raised his hips; he said: This is how the Messenger of Allah (ﷺ) used to prostrate himself.

Sunan Abi Dawud Book 2, Hadith 506 Next Hadith → When the Prophet(ﷺ) prostrated himself, he kept his arms so far away from his sides that if a lamb had wanted to pass under his arms, it could have done so.

Sunan Abi Dawud Book 2, Hadith 508