The Hebrew word massekah means a molten image, cast idol, or metal figure. It derives from the root nasak (H5258, to pour out, cast) and refers specifically to idols made by pouring molten metal into a mold. The most infamous massekah in Scripture is the golden calf at Sinai (Exodus 32:4). The word appears over 25 times in the Old Testament.
The massekah stands at the center of Israel's greatest sin. While Moses received the covenant on Sinai, Aaron fashioned a massekah — a molten calf — and the people worshipped it. The second commandment explicitly forbids making any massekah. The prophets repeatedly condemn molten images as the work of human hands that cannot see, hear, or save. Theologically, the massekah represents the ultimate inversion of worship: instead of the Creator forming humanity, humanity tries to form its own god. The molten image is powerless precisely because it originates in human imagination rather than divine revelation.