1)
What is "Mutzak Echad"?
1.
Rashi: Just like he made one from molten [copper], so he made all of them.
2.
Radak: [Each] was molten at once (Malbim - with its Yados and Misgeros).
2)
What is "Ketzev Echad"?
1.
Radak: This is like Midah Achas. Ketzev refers to something cut to size.
2.
Gra: They were the same, as if they were cut like one.
