Commentary for Exodus 36:1

ועשה בצלאל, and Betzalel carried out all the work, etc. How could the Torah report Betzalel as performing the work when it had not yet informed us that Moses had handed over to him all the donations, and (until verse six in this chapter) the people were still in the process of bringing their various gifts? We are forced to conclude that what the Torah tells us in this verse is that Betzalel and his helpers made all the preparations necessary to carry out the work as soon as the materials would be at hand. He prepared the proper tools. The meaning of the words את כל מלאכת is that they made the tools needed for the work. Different tools are required to perform work on metal, wood, stones and fabrics respectively. We are told in Shabbat 49 that all the 39 categories of work which are prohibited on the Sabbath were performed in connection with the construction of the Holy Tabernacle. It appears from the wording of the Torah that all these tools were prepared on the same day.