והיה לך לאות על ידך ולזכרון ביו עיניך למען תהיה תורת ד' בפיך, כי ביד חזקה הוציאך ד' ממצרים
It says in the Yalkut Shimoni 222 – Klal Yisroel says, “We want to toil in Torah day and night, but what should we do? We don’t have the time to do so.” Hashem answers, “Don tefillin, and it will be as if you are toiling in Torah constantly.” The Gemara in Brachos 35b says that many tried to do like Rebbe Shimon Bar Yochai but were unsuccessful, meaning that many have tried to learn Torah full time, but they were unable to survive. They needed to work in order to earn a living.
The Gemara in Brachos 6a tells us, “רחמנא לבא בעי”, Hashem wants our hearts. If one has a true desire to perform a mitzvah, and due to circumstances beyond his control, he is unable to perform it, it is considered as if he did it. Hashem knows what is truly in a person’s heart, and if the person really wanted to perform that mitzvah and is pained that he was unable to, Hashem considers it as if he performed the mitzvah.
The same is true with learning and toiling in the Torah Hakdosha. One is obligated to toil in the Torah of Hashem all the time; however, many are not zoche to this. One who recognizes that this is what he really should be doing but is unable to and is pained over it, it is considered as if he is toiling in Torah all the time. The Ramban says in a few places regarding the first of the Aseres Hadibros that Hashem said, “I am Hashem Who took you out of Mitzrayim.” Because Hashem took us out of the servitude of Mitzrayim, we must be subservient to Him and accept the yoke of Torah upon ourselves in place of the yoke of Mitzrayim. For had Hashem not taken us out, we would still be subjugated to Mitzrayim. (כתב סופר)
In truth, each and every one of us should be serving Hashem and learning the Torah Hakdosha day and night. However, for most of us, it is impossible to do so. The parshah of Yetzias Mitzrayim is written in the tefillin to rejuvenate within us the knowledge of the obligation that we have of “למען תהיה תורת ד' בפיך,” so that Toras Hashem should be constantly in our mouths. This is what the Midrash is speaking about when it says that Klal Yisroel says to Hashem that they do not have time to toil in the Torah Hakdosha, and to that, Hashem responds that they should put on tefillin. By putting on tefillin, we are showing that we are subjugated to Hashem, as it is written in the tefillin, that Hashem took us out of the servitude of Mitzrayim for us to serve Him. We are to be mityached with the mitzvah of tefillin both through our actions, tefillin shel yad, and our thoughts, tefillin shel rosh, together, to serve Hashem, as a servant serves his master, knowing that everything is the master’s. Since we put on tefillin and recognize that we really should be learning and toiling in the Torah all day, Hashem considers it as if we actually do so.