Which part of a man touches the ground first when he goes down to prostrate

Sayyiduna Abu Hurayrah (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) said: "When one of you prostrates, let him place his knees on the ground before his hands, and let him not kneel down the way a camel kneels."

Ibrahim said: Sayyiduna Umar (may Allah be pleased with him) used to place his knees on the ground before his hands.

Al-Aswad said: Sayyiduna Umar (may Allah be pleased with him) used to put his knees down first.

Nafi' said: When going down into prostration, Sayyiduna Ibn Umar (may Allah be pleased with them both) used to place his knees before his hands, and when he rose, he would lift his hands before his knees.

Abdullah bin Muslim bin Yasar said about his father: When he prostrated, he would place his knees, then his hands, and then his head.

Ibrahim was asked about a man who places his hands before his knees. He disliked it, and he also said: "Only a madman would do such a thing."

Khalid said: I saw Abu Qilabah, when he prostrated, place his knees first, and when he stood up, he would support himself on his hands. And I saw al-Hasan go down beginning with his hands, and when rising he would stand up supporting himself on his hands.

Mahdi bin Maymun said: I saw Ibn Sirin place his knees before his hands.

Ma'mar said: Qatadah was asked: "If a man, going down from bowing into prostration, puts his hands on the ground first, what is the ruling?" He said: "He should do whichever is easier for him."

Abu Ishaq said: When the students of Abdullah (bin Mas'ud) (may Allah be pleased with him) went down into prostration, they would place their knees before their hands.