Knops - literally, "gourds," - i. e. a boss or ball ornament encircled the rim of the bowl in two rows.

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.

Any colocynths (gourds) ran round it under its brim, ten to the cubit, surrounding the sea in two rows; the colocynths "cast in its casting," i.e., cast at the same time as the vessel itself. Instead of פּקעים, gourds (see at 1-Kings 6:18), we find בּקרים דּמוּת, figures of oxen, in the corresponding text of the Chronicles, and in the last clause merely הבּקר, an evident error of the pen, בקרים being substituted by mistake for פקעים, and afterwards interpreted בקרים דמות. The assumption by which the early expositors removed the discrepancy, namely, that they were casts of bullocks' heads, is not to be thought of, for the simple reason that בקרים signifies oxen and not the heads of oxen. How far apart the two rows of gourd-like ornaments were, it is impossible to decide. Their size may be estimated, from the fact that there were ten within the space of a cubit, at a little over two inches in diameter.

Knops - Carved or molten figures: for this word signifies figures or pictures of all sorts. Ten, &c. - So there were three hundred in all. Cast - Together with the sea; not carved. Two rows - It seems doubtful whether the second row had ten in each cubit, and so there were three hundred more; or, whether the ten were distributed into five in each row.