Tanya Chapter 38 part 2. The physical act of the mitzvah and its intention both manifest the Divine will. But there's a difference

While everything of this world is equal in that all are subject to utter and total Divine concealment, the difference between one thing and another becomes vast when we consider the contraction or expansion of the Divine light which flows into each. Generally, this world is divided into four categories, each class corresponding to a different letter of the Divine name Havaya –– one below the other in terms of contraction. We can apply this idea to the speech or act of a mitzvah and its intent. The speech or the act of a mitzvah is its body, the intent is its soul. Being the exposure of Hashem’s will, they each represent total revelation of the Divine and are equal in this respect. However, when it comes to the level at which this exposure is manifest, this is where they become different.