Exodus 36:3 And they received of Moses all the offering, which the children of Israel had brought for the work of the service of the sanctuary, to make it withal. And they brought yet unto him free offerings every morning. - Free Bible Online

      3. they (the workmen)
      received of Moses all the offering, which the children of Israel had brought, &c.--It appears that the building was begun after the first few contributions were made; it was progressively carried on, and no necessity occurred to suspend operations even for the shortest interval, from want of the requisite materials.
      they brought yet unto him free offerings every morning, &c.--Moses, in common with other Oriental magistrates, had his morning levees for receiving the people (see on Ex 18:13); and it was while he was performing his magisterial duties that the people brought unto him freewill offerings every morning. Some who had nothing but their manual labor to give would spend a great part of the night in hastening to complete their self-imposed task before the early dawn; others might find their hearts constrained by silent meditations on their beds to open their coffers and give a part of their hoarded treasure to the pious object. All whose hearts were touched by piety, penitence, or gratitude, repaired with eager haste into the presence of Moses, not as heretofore, to have their controversies settled, but to lay on his tribunal their contributions to the sanctuary of God (2Co 9:7).

JFB.