It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that he used to place his hands on the ground before his knees and used to say that the Messenger of Allah (peace and blessings be upon him) did likewise.
At the time of lowering oneself to prostration, it is abrogated. Some of those among the people of knowledge who did not understand that it is abrogated erred in using it as evidence, so they considered acting upon the report and beginning by placing the hands on the ground before the knees.