A famous pasuk towards the end of Ekev, in Devarim 11:22:
|כב כִּי אִם-שָׁמֹר תִּשְׁמְרוּן אֶת-כָּל-הַמִּצְוָה הַזֹּאת, אֲשֶׁר אָנֹכִי מְצַוֶּה אֶתְכֶם--לַעֲשֹׂתָהּ: לְאַהֲבָה אֶת-ה' אֱלֹהֵיכֶם, לָלֶכֶת בְּכָל-דְּרָכָיו--וּלְדָבְקָה-בוֹ.||22 For if ye shall diligently keep all this commandment which I command you, to do it, to love the LORD your God, to walk in all His ways, and to cleave unto Him,|
where Rashi explains, citing Sifrei:
|and to cleave to Him: Is it possible to say this? Is God not “a consuming fire” (Deut. 4:24)? Rather, it means: Cleave to the disciples and the Sages, and I will consider it as though you cleave to Me. — [Sifrei]||ולדבקה בו: אפשר לומר כן, והלא אש אוכלה הוא, אלא הדבק בתלמידים ובחכמים ומעלה אני עליך כאלו נדבקת בו:|
But Ibn Ezra writes:
ללכת בכל דרכיו -
שלא ישנה ולא יהפוך.
ולדבקה בו -
בסוף והוא סוד גדול.
This is somewhat strange, and he is not being entirely clear, as he calls it a sod. Avi Ezer dances around commenting on this Ibn Ezra, and says he will explain it better in Re'ei.
R' Shmuel Matot puts it succinctly, I think: That the matter has to do with the taking and cleaving of the nefesh hasichlit with the sechel hanifrad once the neshama separates from the body.
More of less, the idea is that this is בסוף, at the end of a person's life, after living in the way the Torah dictates, loving Hashem and walking in his ways.
This would then appear to be an explicit pasuk (working on a peshat level) about Olam Haba. And we know that such pesukim are hard to come by.
Ibn Kaspi, in his sefer dedicated to explaining every sod of the Ibn Ezra, writes something quite similar, I think, but at length:
and Ibn Ezra writes:
אמר בפסוק : .ולדבקה בו בסוף והוא סוד גדול . רצוני בזה, כי
האדם אחרי שילך בדברים שמנהיג השם עולמו לא ישנה ולא
יהפוך. וצריך שידע גודל מעשיו, ואס ידע גדלו, אז שב שכלו
להיות אחד עם מושכלו, ועליו אמר שלמה ברוח הקודש: ישקני
מנשיקות פיהו ועוד נאמר : עפ״י השם יחנו וזה נשיקת השכל שהיא
הנשיקה האמיתית , לא נשיקת השפתים , אך בעבור שתכלית האוהבים
היא הנשיקה בפה ,ע"כ אמר זה דדך משל ובאמת שהיא סוד גדול,
זה רצונו, כי איך יתכן גוף להדבק בשם שאינו כח בגוף, והיא דבר
גדול. ואיך הוא נדבק , וע״כ אמר שהיא סוד .
This sounds very much like Greek philosophy, and Maimonidean philosophy, and kabbalah. The soul returns to cleave to Hashem.
But did Chazal hold of this belief? אם קבלה היא נקבל. But it seems difficult to square this with the objection in Rashi, and the objection in the Sifrei. How could there be an objection of אפשר לומר כן, והלא אש אוכלה הוא? After all, we are dealing here with the soul rather than the guf, and perhaps the soul was initially part of Hakadosh Baruch Hu, and so can cleave to Him?! On the other hand, see what Ibn Kaspi says at the end, asking this very question even in this context and saying that that is why it is gadol and a sod. Perhaps we can say that this is operating on different levels, of peshat, remez, sod, and derash. I am not certain that Chazal operated at all these levels (but perhaps just one level, of Truth), but even if we label one as peshat and one another level, it seems difficult to me. Not because two interpretations cannot be true simultaneously, but because of the way the question in the Sifrei is phrased, as if it is an insurmountable problem which then as a matter of necessity leads to this interpretation of cleaving to the talmidim and chachamim.
Meanwhile, I do not think that Rashi's midrashic explanation or Ibn Ezra's philosophical / mystical explanation is peshat. Rather, on a peshat level, cleaving to Hashem is not meant literally but allegorically. It means to have fealty to Hashem, in heart or mind, or perhaps in action. In that way, it is similar to loving Hashem, earlier in the pasuk.
I came up with this idea independently, Ibn Ezra seems to say as much earlier. For this is not the first time the Torah speaks about devekus to Hashem. In the previous perek, in Devarim 10:20:
[י, כ]את ה' אלהיך תירא -שלא תעברון על מצות לא תעשה.ואותו תעבוד -במצות עשה.ובו תדבק -בלב.ובשמו תשבע -בפה, כאשר הוא מפורש.
Thus, tira implies avoiding negative actions (mitzvot lo taaseh), oto taavod implies performing positive commandments, and bo tidbak imples in one's heart. Why does Ibn Ezra divert in our pasuk in perek 11 from this straightforward reading? Perhaps he was tempted by its placement at the end of the pasuk, and the opportunity to engage in philosophical / mystical derash. Shadal criticized him for doing this on occassion.
Alternatively, perhaps he was dissuaded by ahava earlier in the pasuk. But that would be if he considers the heart to be the seat of emotion. I am not sure that he does, because I am no expert in Ibn Ezra or medieval philosophy. (Based on Ibn Ezra's long commentary on Shemot 23:25, he is in accord with Plato's Timaeus, putting the vegetative soul in the liver, the animal soul in the heart, and the wise/rational soul in the brain.)
Regardless of Ibn Ezra's motivation here in explaining otherwise, I think that on a peshat level, saying that tidbak here is allegorical is just fine.