John Gill Bible Commentary

And whereas thou sawest iron mixed with miry clay,.... That is, iron among the clay; otherwise iron and clay will not mix and cement together, as is affirmed in the latter part of the verse; but as some of these toes were of iron, and others of clay, or some part of them were iron, and some part of them of clay, they shall mingle themselves with the seed of men; the Romans shall mix with people of other and many nations that shall come in among them, and unite in setting up kingdoms; or these kingdoms set up shall intermarry with each other, in order to strengthen their alliances, and support their interests: thus France, Spain, Portugal, and other nations; those of the royal families marry with each other, with such views: but they shall not cleave one to another, even as iron is not mixed with clay; and yet these ties of marriage and of blood shall not cause them to cleave to and abide by one another; but ambition and worldly interests will engage them to take part with each other's enemies, or to go to war with one another, to the weakening and hurting each other; and thus the potsherds of the earth will dash one another to pieces; and those who are more powerful, like the iron, will trample the weaker like miry clay under their feet.