عن البَرَاء بن عَازب رضي الله عنهما مرفوعًا: «إذا سَجَدت فضَع كفَّيك وارْفَع مِرْفَقَيْك».
[صحيح] - [رواه مسلم]
Al-Barā' ibn ‘Āzib (may Allah be pleased with him) reported that the Messenger of Allah (may Allah’s peace and blessings be upon him) said: "When you prostrate, place your palms (on the ground) and raise your elbows."
Sahih/Authentic. - [Muslim]
This Hadīth says to place the palms on the ground and lift the arms from the ground, spread them away from body when prostrating. This position is akin to humbleness, far away from resembling the position of the lazy or an animal. Prostration with one’s arms flat on the ground resembles the way wild beasts lie down. In addition, it gives the impression of indifference to prayer and lack of enthusiasm for it. Maymūnah, (may Allah be pleased with her) narrated that the Messenger (may Allah's peace and blessings be upon him) used to keep his arms away from his sides, to the point where if an animal wanted to pass under them, it could do so.