C. F. Keil and Franz Delitzsch on Exodus 25:1-3

Exo 25:1-3 (cf. Exo 35:1-9). The Israelites were to bring to the Lord a heave-offering (תּרוּמה from רוּם, a gift lifted, or heaved by a man from his own property to present to the Lord; see at Lev 2:9), “on the part of every one whom his heart drove,” i.e., whose heart was willing (cf. לבּו נדיב Exo 35:5, Exo 35:22): viz., gold, silver, brass, etc.