Isaiah 45:9 (b) This is typical of human beings who are shaped and molded in the hands of the Lord. (See also Isaiah 64:8).
Jeremiah 18:6 (a) It represents Israel as a nation in the hands of the Lord for Him to alter, mold and make as He pleases.
Daniel 2:42 (b) Here the "clay" represents the friability and inconstancy of the nations at the end of the age. They will be easily broken and will have little cohesion with other nations as clay is easily broken and will not adhere to iron.
John 9:6 (c) This probably indicates the fact that the Lord shuts our eyes effectually to the things of this earth that He may open them to see His face and rejoice in His presence, and enjoy spiritual realities.