Daniel 2:41-43

Whereas you saw the feet and toes, partly of potter’s clay and partly of iron, the kingdom shall be divided; yet the strength of the iron shall be in it, just as you saw the iron mixed with ceramic clay. And as the toes of the feet were partly of iron and partly of clay, so the kingdom shall be partly strong and partly fragile. As you saw iron mixed with ceramic clay, they will mingle with the seed of men; but they will not adhere to one another, just as iron does not mix with clay.