The precious sons of Zion - The whole nation was consecrated to God, and formed “a kingdom of priests” Exodus 19:6 : in this respect, a type of the Christian Church 1 Peter 2:5.
Comparable to fine gold - literally, “weighed with” solid gold, and so equal to their weight in it. With this is contrasted the hollow pitcher easily broken, and made of materials of no intrinsic value.