John Gill Commentary 1 Kings 7:24

"And under the brim of it round about there were knops which did compass it, for ten cubits, compassing the sea round about: the knops were in two rows, cast when it was cast." — 1 Kings 7:24 (ASV)

And under the brim of it round about there were knops
compassing it
Of an oval form, and therefore the Targum calls them figures of eggs; in (2 Chronicles 4:3) they are said to have the similitude of oxen, being like the heads of oxen, and the other parts oval; or these were in the form of gourds, as sometimes the word is rendered, (2 Kings 4:39) which had on them the figures of the heads of oxen, and might serve as cocks to let out the water:

ten in a cubit, compassing the sea round about it ;
and as the circumference was thirty cubits, there must be three hundred of these in the circuit:

the knops were cast in two rows when it was cast ;
for these were cast together with the sea, and being in two rows, there must be in all six hundred of them.