Or HaChaim on Exodus 35:2/אור החיים על שמות ל״ה:ב׳

1 ששת ימים תעשה מלאכה, "during six days work shall be performed, etc." The reason the Torah emphasises the work to be performed on the weekdays may simply be a hint that if one observes the seventh day as a holy day, the work required for our maintaining ourselves during the subsequent six days will take care of itself.

2The Torah may also wish to remind us that performance of work on the Sabbath is prohibited regardless of whether it is performed by a Jew or by a Gentile on his behalf. The vocalisation of the word te-asseh (passive form), is intended to convey that whereas it is permissible for a Jew to have his work performed by Gentiles during the week, on the Sabbath it must not be performed at all. This would correspond to the opinion expressed in the Talmud that if one tells a Gentile to perform work for one on the Sabbbath, one violates a biblical prohibition (Mechilta Parshat Bo). The reason the Torah writes ששת instead of בששת, is to remind us that work performance during the six days of the week is a מצוה, a positive commandment.

3There is also a lesson here that the success of the work performed during the six days of the week depends on the observance of the seventh day as a holy day. The reason is that the Sabbath is the soul of the world as we explained in our introduction to Genesis on Genesis 2,2.