The Book of Exodus completes with a description of the building of the Mishkan. Just before Moses leads the Israelites in it's construction, he reminds them that the Sabbath comes first. In Rashi's words, the Tabernacle does not supersede the Sabbath. This is an important precedent for the Mussar masters, who develop two ideas:
You should not commit a sin to perform a mitzvah: observance of particular mitzvot should not lead one to hurt, injure, or be careless about one's responsibilities to other people. Service to God, especially in the form of helping other people. is more important than having the kinds of spiritual feelings or experiences that the Mishkan evoked.
Shemot (35: 2) (Robert Alter, trans.) These are the things that the LORD has charged to do: Six days shall tasks be done and on the seventh day there shall be holiness for you, an absolute sabbath for the LORD.
Rashi Moses precedes the commandment to make the Tabernacle with the Sabbath commandment, to let them know that the building of the Tabernacle does not supersede the Sabbath.
Rabbi Shlomo Wolbe [A lesson of the Golden Calf is that good intentions do not justify bad actions.] Therefore the Torah warns Bnei Yisrael: Even though you are commanded to built a Mishkan, which is to act as an abode for Hashem and a means of connecting with Him, it should not be build on Shabbos, for this would constitute [a mitzvah that came about through sin].
How was the Golden Calf based on good intentions? This concept formed one of the focal points of Rav Yisrael Salanter's teachings. A person must ensure that his mitzvos are not performed by a way of aveiros [sins]. Rav Yisrael would depict a scene in which a maggid came to town to deliver a mussar shmuess [lecture]. Everyone in the town was interested in hearing his words of wisdom, and they rushed to the shul where the speech was being held. In their haste, one person knocked over a passerby, another got angry because someone cut him off, and so on. Yes, they were running to perform a mitzvah -- to hear words that would help them improve their avodas Hashem [service to God] -- but at what cost? ... No matter how noble the goal, trampling on other people is never the way to achieve it.
Can you think of examples you've seen or experienced?
Pirkei Avot (4: 17) He [Rabbi Yaakov] would say: One hour of repentance and good deeds in this world is better than all the time in the world to come. And one hour of pleasure in the world to come is better than all the time in this world.
What do you think is meant by this saying?
Rabbi Israel Salanter Spiritual needs are more elevated than material needs, but the material needs of another are an obligation of my spiritual life.
Does this statement help clarify Rabbi Yaakov's aphorism?
Rabbi Shlomo Wolbe Basking in the Shechinah's presence [God's presence] would seem to be the pinnacle of spirituality attainable in this world. However, Chazal [the Sages] tell us that the mitzvah of hachnasas orchim [hospitality] takes precedence over receiving the Shechinah.
One Yom Kippur when [Rav Wolbe] was studying in the Mirrer Yeshivah in Europe, before Mussaf the chazzan sent a number of students to check on one of the boys who was ill. "This is the obligation of the day," the chazzan explained. Our obligation in this world is to perform mitzvos, and that takes precedence over davening Mussaf on the holiest day of the year.
[Sometimes we encounter something] that enlightens us to the spiritual levels we can attain. However, these revelations alone are not our ultimate goal. We must take our feelings and turn them into actions, thereby accomplishing more than one who has the awesome opportunity to speak to the Shechinah!
...spiritual acquisitions are obtained through actions done on behalf of others.
Rav Wolbe mentions a practical example -- can you think of other actions that might exemplify "the obligation of the day" of repentance?