If we aren't obligated in 613, why ask for reward for 613?

Question

This is based on some preconceived notions I have so if my premises are wrong, please let me know.

I am not bound to all 613 mitzvot. I get this from here, and through a look at the Rambam's list. Some simply don't and can't apply to me -- and this includes negatives (a woman shouldn't wear men's clothing) and positives (that a Kohein should put on the proper garments for the service).

I know that (from reading related questions) there is some reward for fulfilling mitzvot I am not obligated in, though less than for someone who is obligated in them, but as far as I understand, I do not get a reward for mitzvot that I can't fulfill (unless one counts "learning about them" as equivalent), or even ones that don't apply to me that I DO fulfill (if I wear the priestly garments and perform the service, I can't imagine that I get any reward for kiyum hamitzvah - in fact, I would assume that it would be problematic).

Why then do I ask that my performance of certain mitzvot should be considered as if I fulfilled all 613? I say things like

כְּאִלּוּ קִיַּמְתִּיהָ בְּכָל פְּרָטֶיהָ וְדִקְדּוּקֶיהָ וְכַוָּנותֶיהָ וְתַרְיַ"ג מִצְות הַתְּלוּיִם בָּהּ.

The Artscroll translation is May it be your will that (insert commandment here) be as worthy "as if I had fulfilled it in all its details, implications and intentions as well as the six hundred and thirteen commandments that are dependent on it."

Why do I want to be considered as if I had fulfilled 613 mitzvot when some of them are not meant for me and, were I to fulfill them, I would not receive any reward (and it might even be a bad thing)?

Answer 1

You didn't specify when you are saying this formulation, but if you are saying it when performing the mitzvah of tzitzit and the mitzvah of tefillin we can perhaps explain it in a different sense. Both tzitzit and tefillin are associated with all the mitzvot:

Menachot 43b

תניא אידך וראיתם אותו וזכרתם את כל מצות ה' שקולה מצוה זו כנגד כל המצות כולן ותניא אידך וראיתם אותו וזכרתם ועשיתם ראיה מביאה לידי זכירה זכירה מביאה לידי עשיה

And another [Baraitha] taught: ‘That ye may look upon it and remember all the commandments of the Lord’: this precept is equal to all the precepts together. And another [Baraitha] taught: ‘That ye may look upon it and remember... and do them’: looking [upon it] leads to remembering [the commandments], and remembering leads to doing them.

(Soncino translation)

Midrash Seichel Tov Shemot 13:16

גדולה היא יציאת מצרים שצריכה אות וטוטפות להזכירה כנגד כל המצות

Thus, when performing these mitzvot it makes sense to mention 613 mitzvot because all 613 mitzvot are connected to the current mitzvah. Even if you personally cannot fulfill a particular mitzvah, every mitzvah is still associated with tzitzit and tefillin.