Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) says: A man asked the Noble Prophet (peace and blessings be upon him) about prayer. The Messenger of Allah (peace and blessings be upon him) said: "Cleanse between the fingers of the hands and feet." By this, he meant that ablution should be performed completely. Furthermore, the Prophet (peace and blessings be upon him) also said to him: "When you bow (in ruku‘), place your palms on your knees and be at ease in the position of ruku‘, and when you prostrate (in sujud), place your forehead firmly on the ground, until you feel the thickness of the earth."
Hadith Takhrij«اسناده حسن۔ أخرجه ابن ماجه: 447، والترمذي: 39، (انظر مسند أحمد ترقيم الرسالة: 2604)(693) اسناده صحيح۔ أخرجه ابوداود: 173، وابن ماجه: 665 ، (انظر مسند أحمد ترقيم الرسالة: 12487 ترقیم بيت الأفكار الدولية: 2604»
Brief Explanation
Benefits: … The meaning of the last sentence is that during prostration (sajdah), the forehead should press firmly against the ground, and this will be possible if, according to the Sunnah, the arms are kept well apart from the sides, so that the nose and forehead can rest properly on the ground. When washing the hands and feet, the fingers should be interlaced (khilal) so that their inner parts do not remain dry.