Son of Cows

The Torah describe Leah as follows: "And Leah's eyes were רכות" (Gen. 29:17).

Translating the word רכות is difficult. Ibn Ezra quotes a Ben Ephraim (evidently a Karaite) who associates the word with ארכות (long). Ibn Ezra rejects this suggestion and dismisses Ben Ephraim as missing an aleph. In other words, Ben Ephraim suggests that the word ארכות is missing an aleph so Ibn Ezra says that Ben Ephraim himself is missing an aleph and is a בן פרים (son of cows).

However, the Gemara (Bava Basra 123a) quotes R. Eliezer who explains the above verse as meaning that Leah's ultimate rewards for her descendants were ארכות (long), i.e. extensive. This is similarly brought down in Tanhuma Yashan (cited in Torah Shelemah ad loc.) in the name of R. Yohanan. Are R. Eliezer and R. Yohanan also so mistaken as to be foolish sons of cows, like Ibn Ezra calls Ben Ephraim?

The Maharsha suggests that R. Eliezer (and hence, R. Yohanan also) did not associate רכות with ארכות but with ריכא. Their explanation is entirely different from Ben Ephraim's.

I would like to propose an entirely different approach to distinguishing between the explanation in the Gemara and that of Ben Ephraim's. Perhaps R. Eliezer and R. Yohanan did, indeed, connect רכות with ארכות. However, they were speaking on the level of Derash, in which associations of the basic consonantal structure is sufficient to equate words. Ben Ephraim, however, was working within the level of Peshat and, therefore, his suggestion falls far short of the grammatical precision required.

I believe that this might be to what R. Ya'akov Kamenetsky referred in his Emes Le-Ya'akov to the above verse, the editor's footnote notwithstanding.