“Clay ” means
Clay : As the sediment of water remaining in pits or in streets, the word is used frequently in the Old Testament. (Psalms 18:42; Isaiah 57:20; Jeremiah 38:6) and in the New Testament, (John 9:6) a mixture of sand or dust with spittle. It is also found in the sense of potter's clay. (Isaiah 41:25) The great seat of the pottery of the present day in Palestine is Gaza, where are made the vessels in dark-blue clay so frequently met with. Another use of clay was for sealing. (Job 38:14) Our Lord's tomb may have been thus sealed, (Matthew 27:66) as also the earthen vessel containing the evidences of Jeremiah's purchase. (Jeremiah 32:14) The seal used for public documents was rolled on the moist clay, and the tablet was then placed in the fire and baked.