True reason behind particular structure of any ibadah ritual cannot be known with certainty. It is something prescribed by God as He deems fit and only He can do this. The only difference is that some have been made obligatory and transmitted as Sunnat e Sabita (through ijma and tawatur) and others have been optional and are extracted from akhbar-i-ahad. The structure of rituals like one ruku, two sujood, number of rakats, the way to perform wuzu etc. etc. in those specific ways have no basis for a human mind whatsoever. Therefore, ‘tabbudi amoor’ (matters of ibadah) cannot be comprehended and enumerated by a human mind unless told by the God himself. Later, once we know the acts, we can come up with rational and logical explanation for such acts. Matters of ibadah (also known as ‘Tabbudi amoor’) are to be followed in an ‘as is‘ format, as they have been sanctioned by the God Himself as deemed appropriate and have been transmitted through ijma and tawatur. While following these directives, one may look into the wisdom or rationale behind particular acts involved in religious rituals.
Please also refer to the following response by Ghamidi Sahab:
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