Our Gemara on Amud Aleph derives the ethical directive to go beyond the letter of the law, Lifnim Mishuras Hadin, from the following verse (Shemos 18:20):

 

וְהִזְהַרְתָּ֣ה אֶתְהֶ֔ם אֶת־הַחֻקִּ֖ים וְאֶת־הַתּוֹרֹ֑ת וְהוֹדַעְתָּ֣ לָהֶ֗ם אֶת־הַדֶּ֙רֶךְ֙ יֵ֣לְכוּ בָ֔הּ וְאֶת־הַֽמַּעֲשֶׂ֖ה אֲשֶׁ֥ר יַעֲשֽׂוּן

 

“And you shall show them the way wherein they must walk, and the deeds that they shall do”

 

Says the Gemara, “The deeds that they shall do”; this is referring to conducting oneself beyond the letter of the law.

 

The commentaries (Malbim, Maharsha Bava Metzia 30b) have difficulty explaining what is the implication from the text. How does “The deeds that they shall do” connote going  beyond the letter of the law?

 

Rav Yosef Engel (Gilyonei Hashas) explains that the Hebrew clause “asher”, which means something akin to “that is” or “that will be” has a connotation of something that is optionally done (see Gemara Makkos 8a, where they derive that the accidental death described in the verse came from an action that was not involved in an obligatory mitzvah (Devarim 19:5): “And whoever comes with his peer into the woods to chop trees…”, exempting someone who commits manslaughter when performing a mitzvah from exile.)

 

Therefore, Rav Yosef says the implication from the phrase “The deeds that they shall do”, is deeds that are to be done, but still undertaken voluntarily.

 

This is an important idea regarding taking on various extra chumros in life.  If you can take it on out of a sense that this is something that you naturally want to do, and can do it without bitterness and resentment, go for it.  However, even though it is a moral obligation to go beyond the letter of the law and not just extra credit, so to speak, (see Reshimos Shiurim, ibid), one must still not do it in a manner that feels to be a burden. As Yersushalmi (Nedarim 9:1) exhorts: “Is it not enough for you what the Torah already forbade?!”

 

The Shalah (Torah Shebiksav Sefer Vayikra Torah Ohr Kedoshim) says that each person has their own Torah. There are too many particulars and judgment calls about when to hold back from pleasures and when to indulge that the Torah cannot give custom and specific directions, rather each person must decide what works properly according to his or her temperament and inclinations.