אברים שפלגת בנו
The word "שפלגת" can have two implications. The first implication is separation and opposition as in Tehilim 55, פלג לשונם. This word is used often in Gemara במאי קמפלגי, פליגא. Further, this implication is involved in the title חכם מופלג, that such a person is separated to a higher level than others in terms of wisdom and knowledge (also, עשיר מופלג, etc.). According to this first implication, the verse infers that we have various separated limbs yet we unite them to praise the Creator.
The second implication of "שפלגת" is one that investigates and arranges items to their parts and functions, like the verse (Bereshis 10, 25) בימיו נפלגה הארץ. It is understood that this verse means that in his days the land was arranged according to the differing settlements. According to this second implication, we can understand the phrase in the prayer means that one’s limbs are arranged according to each function and proper place, and yet unite to praise HaShem.
