Numbers 5:23,24

And the priest shall write these curses in a book, and he shall blot them out with the bitter water:

Write these curses in a book. The imprecations, along with her name, were inscribed in some kind of record-on parchment, or more probably on a wooden tablet.

Blot them out with the bitter water, х maachaah (H4229)] - wipe off, blot out. Here it is presumed that the material on which the writing was did not dissolve by the water, but only that the writing was thereby washed off. In this case paper was excluded. On the other hand, the writing must have been with ink, otherwise it could not have been so easily obliterated-a circumstance which also excludes the byssus (Havernick's 'General Historico-Critical Introduction to the Old Testament'). If she were innocent, they could be easily erased, and perfectly harmless; but if guilty, she would experience the fatal effects of the water she had drunk.