This word is used of sediment found in pits or in streets (Isaiah 57:20, of dust mixed with spittle (John 9:6), and of potter’s clay (Isaiah 41:25; Nahum 3:14; Jeremiah 18:1-6; Romans 9:21).
Clay was used for sealing (Job 38:14; Jeremiah 32:14). Our Lord’s tomb may have been thus sealed (Matthew 27:66). The practice of sealing doors with clay is still common in the East.
Clay was also in primitive times used for mortar (Genesis 11:3).
The “clay ground” in which the large vessels of the temple were cast (1 Kings 7:46; 2 Chronicles 4:17) was a compact loam fitted for the purpose. The expression literally rendered is, “in the thickness of the ground,” meaning, “in stiff ground” or in clay.