מֵאַבְנֵי (Gen. 28:11) and הָאֶבֶן (Gen. 28:18)

Question

Do any commentaries mention a reason for the plural "stones" in Gen. 28:11 and the singular "stone" in Gen. 28:18?

In Gen. 28:11, it says that Ya'akov took "of the stones" (מֵאַבְנֵי) and put them for his pillows, while in Gen. 28:18 it says that he took the "stone" (הָאֶבֶן) that he put for his pillows.

Is there any significance to this change in number?

Answer 1

Rashi explains (translation from chabad.org) based on the Gemora in Chullin:

He arranged them in the form of a drainpipe around his head because he feared the wild beasts. They [the stones] started quarreling with one another. One said, “Let the righteous man lay his head on me,” and another one said, “Let him lay [his head] on me.” Immediately, the Holy One, blessed be He, made them into one stone. This is why it is stated (verse 18):“and he took the stone [in the singular] that he had placed at his head.” [From Chullin 91b]

However, others (Ibin Ezra, Radak, Ralbag, Zohar Chadosh 27b and see Tosfos to Chullin 91b) note that there is no contradiction at all. 28:11 states "מאבני" - "of the stones" and not "אבני" - "stones", and could therefore be explained that he took one of the stones that were there.