Praise be to Allah.
The scholars have differed as to how one should go down in sujood, whether one should go hands first or knees first. According to the Hanafis, Shaafais and one opinion narrated from Ahmad, the person who is praying should go down on his knees first, then on his hands. Al-Tirmidhi thought that this was the opinion of the majority of scholars, and said in his Sunan (2/57): This is how it is done according to the majority of scholars: they think that a man should go down on his knees before he puts his hands down, and when he gets up he should raise his hands before his knees. Those who express this opinion take as evidence the hadeeth of Waail ibn Hajar, who said: I saw the Messenger of Allaah (peace and blessings of Allaah be upon him), when he did sujood, putting his knees down before his hands, and when he got up he raised his hands before his knees.(Reported by Abu Dawood, al-Tirmidhi, al-Nisaai, Ibn Maajah and al-Daaraqutni (1/345). He said: The only one who narrated it was Yazeed ibn Haaroon from Shurayk. Nobody reported from Aasim ibn Kulayb except Shurayk, and Shurayk is not qawiy (strong). Al-Bayhaqi said in al-Sunan (2/101): its isnaad is daeef (weak). Al-Albaani classed it as daeef in al-Mishkaat (898) and al-Irwa (2/75). Other scholars classed it as saheeh, such as Ibn al-Qayyim (may Allaah have mercy on him) in Zaad al-Maaad). Among those who thought that one should go down into sujood knees first were Shaykh al-Islam Ibn Taymiyah and his student Ibn al-Qayyim; contemporary scholars who favour this view include Shaykh Abd al-Azeez ibn Baaz and Shaykh Muhammad ibn Saalih al-Uthaymeen.
Maalik, al-Awzaai and the scholars of hadeeth thought that one should go into sujood hands first, based on the hadeeth of Abu Hurayrah (may Allaah be pleased with him), who said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said, When any one of you prostrates, let him not go down as the camel does; let him put his hands down before his knees.(Reported by Ahmad (2/381), Abu Dawood, al-Tirmidhi, and al-Nisaai. Al-Nawawi said in al-Majmoo (3/421): it was reported by Abu Dawood and al-Nisaai with a jayyid isnaad. It was classed as saheeh by Shaykh al-Albaani in al-Irwa (2/78), who said: This is a saheeh isnaad, all of whose men are thiqaat, the men of Muslim, apart from Muhammad ibn Abd-Allaah ibn al-Hasan, also known as al-Nafs al-Zakiyyah al-Alawi, who is thiqah)
Shaykh al-Islam Ibn Taymiyah made a valuable comment on this matter in al-Fataawa (22/449): Praying in both ways is permissible, according to the consensus of the scholars. If a person wants to go down knees first or hands first, his prayer is valid in either case, according to the consensus of the scholars, but they disputed as to which is preferable.
The scholar should act upon whichever opinion he believes is more likely to be correct, and the ordinary Muslim should follow the opinion of a scholar whom he trusts. And Allaah knows best.