Jeremiah 51:63 - Ellicott's Commentary On The Whole Bible

Thou shalt bind a stone to it. — The meaning of the symbolic act, which has its parallel in the girdle of Jeremiah 13:1-7, in the potter’s vessel of Jeremiah 19:10, and in the yokes of Jeremiah 27:2, is explained in the following verse. The parchment roll by itself might have floated, and been picked up and read, and so the stone was tied to it that it might sink at once, and thus prefigure the destruction of the city. (Compare the reappearance of the symbols in Revelation 18:21, in connection with the destruction of the mystical Babylon.)