What are "Peka'im"?
Rashi citing Targum Yonasan: The shapes of eggs 1 .
Radak: Divrei ha'Yamim II, 4:3 says that they were the forms of cattle 2 . The bodies were round like eggs, and the faces were like cattle faces.
Gra (24): These are the shapes of cattle (verse 25). Peka'im is like Beka (half), for only one side was visible; the other side faced the Yam's wall.
Malbim: The form of eggs protruded, and the forms of cattle were carved into them.
'Rashi' (Divrei ha'Yamim II, 4:3): They were ornamental knobs like people put on cups.
Radak explains that "Bekarim" there teaches about the Peka'im around the Yam; "Bakar" in verse 4 there teaches about the forms of cattle on which the Yam stood. (PF)
What is "mi'Tachas li'Sefaso"?
Rashi: It is in the three bottom Amos, which were square; the top two Amos were circular (Eruvin 14b). This is the only way to resolve that its volume was 2000 Bas (6000 Sa'im) (verse 26).
Gra: It is under the brim (the top of the Yam, which was round).
Why does it say "Eser b'Amah"?
Rashi: The Yam was 10 Amos on every side [Radak - where it was square].
Malbim: There were 10 Peka'im (egg shapes) in every Amah.
Where were the two rows of Peka'im?
Rashi: They were around the three bottom Amos, which were square.
Gra: They were in the top two 'rows' (each an Amah tall) above, where the Yam was round. 1
Malbim: One was around the three bottom Amos, which were square, and one was near the top, where the Yam was round.
Gra: The top row was around the Yam and attached to (molten with) it. The bottom row rested on the roof of the lower part of the Yam, which was square, where it extends past the circular top part of the Yam. (He holds that the Peka'im are the cattle mentioned in verse 25. He explains esoterically "veha'Yam Aleihem mil'Ma'alah"; refer to 7:25:2:1. I do not know how he explains "Omed Al Shnei Asar Bakar." - PF)
What is the meaning of "Yetzukim"?
Radak: They were formed by melting the copper [into the mold] together with the Yam. They were not attached afterwards.
