Musar zu Jeschijahu 58:13

The details of these laws according to their differences are explained by the Halachic deciders (Poskim) in their books. All of these details are equal for all us with respect to their obligation and requisite watchfulness. That which is difficult on the masses to guard is abstaining from business occupation and conversation. This prohibition is stated in the words of the prophet (Isaiah 58:13): "if you honor it, abstaining from your own ways, not pursuing your affairs and speaking words about them". The general principle is that whatever is forbidden to do on the Sabbath is forbidden to strive after or mention verbally.

Included in this category, is honoring the Sabbath and Festivals. For whoever gives much honor to these, certainly brings gratification to his Maker, who thus commanded us: "you shall honor it" (Isaiah 58:13).

But there are some additional matters of Piety, which if a person were to do before the common people, they will laugh at him and ridicule him, thereby sinning and incurring punishment through him, and this is something he could have abstained from doing since these things are not complete obligations. Thus, for such things, it is certainly more proper for the Chasid to abstain from it than to do it. This is what scripture says: "and walk discreetly with your G-d" (Michah 6:8). Many great Chasidim abstained from their pious practices when in the presence of the common masses because it appears like arrogance.