The Gemara Discusses a challenge of how to understand what could possibly be equated to the fear of G-d. The reason why this puzzle arises is that in Hebrew there is a conjunctive word that you cannot easily translate into English, the word “Es”, which roughly translates into a verbal signal that some thing is coming along with the item explicitly named. So for example when the verses honor thy father and thy mother, there is this additional clause that implies honor along with the father and the mother. In that case, it comes to include the older sibling. However when it says and you shall fear the Lord, the question is, since it also uses that clause it means something like you shall fear along with the Lord. The question is what could be added and be equivalent to fear of the Lord?

As it was taught in a baraita: Shimon HaAmmassoni, and some say that it was Neḥemya HaAmmassoni, would interpret all occurrences of the word et in the Torah, deriving additional halakhot with regard to the particular subject matter. Once he reached the verse: “You shall be in awe of [et] the Lord your God; you shall serve Him; and to Him you shall cleave, and by His name you shall swear” (Deuteronomy 10:20), he withdrew from this method of exposition, as how could one add to God Himself? His students said to him: Rabbi, what will be with all the etim that you interpreted until now? He said to them: Just as I received reward for the interpretation, so I shall receive reward for my withdrawal from using this method of exposition. The word et in this verse was not explained until Rabbi Akiva came and expounded: “You shall be in awe of [et] the Lord your God”: The word et comes to include Torah scholars, and one is commanded to fear them just as one fears God. In any case, Shimon HaAmmassoni no longer derived additional halakhot from the word et.

כִּדְתַנְיָא: שִׁמְעוֹן הָעַמְסוֹנִי, וְאָמְרִי לַהּ נְחֶמְיָה הָעַמְסוֹנִי, הָיָה דּוֹרֵשׁ כׇּל ׳אֶתִּים׳ שֶׁבַּתּוֹרָה, כֵּיוָן שֶׁהִגִּיעַ לְ״אֶת ה׳ אֱלֹהֶיךָ תִּירָא״ פֵּירַשׁ. אָמְרוּ לוֹ תַּלְמִידָיו: רַבִּי, כׇּל ׳אֶתִּים׳ שֶׁדָּרַשְׁתָּ מָה תְּהֵא עֲלֵיהֶן? אָמַר לָהֶם: כְּשֵׁם שֶׁקִּבַּלְתִּי שָׂכָר עַל הַדְּרִישָׁה, כָּךְ אֲנִי מְקַבֵּל שָׂכָר עַל הַפְּרִישָׁה. עַד שֶׁבָּא רַבִּי עֲקִיבָא וְדָרַשׁ: ״אֶת ה׳ אֱלֹהֶיךָ תִּירָא״ — לְרַבּוֹת תַּלְמִידֵי חֲכָמִים.

The Maharsha raises a question, why did Shimon HaAmmassoni wait until he reached the verse of fearing Hashem, why did he not encounter a similar challenge with an earlier verse in Deuteronomy (6:1) which refers to loving G-d? (ואהבת את ה' אלהיך )

The Kedushas Levi (Chayyey Sarah) answers that finding a love object comparable to G-d is not as difficult as someone to fear. The reason for this depends on the fundamental difference in the intent of the two directives: the fear of G-d and the love G-d. One can fear the unknown, but one cannot truly love the unknown. Therefore, the verse in regard to fear of G-d is meant literally, but the verse in regard to love of G-d is already not meant in its complete sense. 

Therefore, the directive to fear G-d should absolutely and only apply to G-d  since what other kind of fear would be comparable to his greatness and majesty? However, love only can come from knowing some thing. Since we cannot truly know G-d The first must be speaking in a figurative sense, as in we wish to be affiliated and be connected with him in some incomplete way. If that is so, then there are many people who we can also love in that manner and certainly it is not difficult to find comparable forms of love. This is why Shimon HaAmassoni did not have a problem with the directive to love G-d.

Realizing that love is contingent on truly knowing someone, I will add my own twist. We can never truly know anyone and so just as our love for G-d in the fullest sense is impossible, so is love for another person because we never can fully know another person. Because the love is always a work in progress and never complete, it is appropriate to compare love for a spouse, love for a child, love for parents to love for G-d and like fear which in many respects requires less nuance and less Emotional sophistication. 

קדושת לוי חיי שרה 

השמר פן תשיב את בני שמה  (בראשית כד, ו). וכן אמר ה' ליצחק גור בארץ הזאת (בראשית כו, ג). כי הכלל יראה הוא מדבר גדול ממנו ובאמת אסור לירא מקטן ממנו כמו הירא מדבר אחר זולת השם יתברך הוא כמו העובד עבודה זרה חס ושלום ובאמת מדת אהבה יכול לאהוב הקטן ממנו כגון לאהוב את בני ביתו. ובזה יתורץ דקדוק מה שאמרו בגמרא (פסחים כב:) דרבי שמעון דרש כל את שבתורה כיון שהגיע לאת ה' אלהיך תירא פירש עד שבא ר' עקיבא ודריש לרבות תלמידי חכמים. כי באמת מדת היראה יכול לומר אני ירא ממך אפילו ממי שגדול ממנו אבל מדת אהבה כלום יכול אדם לומר למלך גדול ונורא אני אוהב אותך, כי זה איננו שייך כלל אבל יכול לומר אני אוהב להיות אתך בביתך ולעבוד לך אבל מדת יראה יכול לומר למלך אני ירא ממך. ובאמת קשה למה לא פירש מן ואהבת את ה' אלהיך (דברים ו, ה) ובזה מתורץ, דבאמת ואהבת את ה' אלהיך, בו שייך לומר את ה' אלהיך, כלומר לעבוד את ה' אלהיך ולהיות יושב בביתו אבל ביראה לא שייך לומר את ה' אלהיך תירא, כלומר לירא להיות את ה' אלהיך רק לפני ה'. וזה פירוש עד שבא ר' עקיבא ופירש לרבות תלמידי חכמים, כיון שהוא עובד ה' יש לירא מפניו. ובזה יבואר דבאמת אברהם מדתו היה במדת אהבה יכול להיות אפילו בחיצוניות כגון לאהוב בני ביתו ולגמול עמהם חסד ובזה היה יכול לילך חוץ לארץ אבל יצחק שהיה מדתו מדת היראה לא היה רשאי להיות בחוץ לארץ. וזהו שאמר פן תשיב וכו', וכן אמר השם יתברך ליצחק גור בארץ הזאת, אי אתה רשאי לילך לחוץ לארץ מחמת מדתך מדת יראה:

We ‎have a standing rule according to which it is permissible to be ‎afraid of something or someone bigger than oneself, whereas it is ‎forbidden to be afraid of someone smaller than oneself. In other ‎words, whereas it is permissible to be afraid of G’d, it is not ‎permissible to be afraid of anyone other than G’d. This is why all ‎manner of idol worship is prohibited.‎

The attribute of love enables one to love those who are ‎‎“smaller” than we are, notably the members of our household ‎who depend on us. When we keep this rule in mind we will be ‎able to understand a story in the Talmud Kiddushin 57 ‎where it is related that Shimon ben Ammasuni undertook to ‎explain the meaning of each word ‎את‎ in the Torah, proving that ‎the word invariably includes something that the Torah had not ‎spelled out specifically. However, when he came to the line ‎‎(Deuteronomy 6,13) ‎את ה' אלוקיך תירא‎, “you are to revere the Lord ‎your G’d,” he was stymied, not knowing what the word ‎את‎ in that ‎line could possibly add, as it is forbidden to revere anyone other ‎than the Lord. His students asked him if he thought that all the ‎explanations that he had found for the other times that the word ‎את‎ occurs should be disregarded? He replied that “just as the ‎Torah promises a reward for explaining its intricacies, so it ‎rewards those who refrain from offering explanations that are not ‎appropriate.” In the meantime, Rabbi Akiva who had heard of ‎Shimon ben Ammasuni’s dilemma, said that even this ‎את‎ added ‎an additional meaning to the verse in which it appeared, ‎suggesting that the Torah scholars deserve to be revered also. ‎Rabbi Akiva was able to offer this explanation since Torah ‎scholars are “greater” than the ordinary people consulting them, ‎so that they fit the principle that it is allowed to revere, be in awe ‎of, people that are greater than oneself. This is a basic difference ‎between the attribute of reverence, ‎יראה‎, and the attribute of ‎אהבה‎, love. While it is in order to say: “I am afraid of you,” to ‎someone more powerful than oneself, a king for instance, it is not ‎in order to say to such a king: “I love you.” It is, however, ‎permissible to say to such a king: “I love to be in your house,” “I ‎love to serve you,” etc.

The above distinction explains why Shimon ben Amassuni ‎had not found a problem with the word ‎את‎ in Deuteronomy 6,5 ‎where the Torah writes: ‎ואהבת את ה' אלוקיך‎, “you shall love the ‎Lord your G’d.” He understood this verse as not applying to G’d’s ‎essence, but to attributes of G’d, attributes worth emulating ‎because they make Him lovable. This is also why Rabbi Akiva was ‎able to resolve his difficulty when he suggested that reverence for ‎Torah scholars, who are an extension of G’d from Whom they ‎received their knowledge and stature, therefore qualify for a ‎portion of reverence that is due to their Master. Seeing that the ‎Torah scholar is a servant of G’d, he too is entitled to some of his ‎Master’s reflected glory.‎

Avraham’s major attribute was ‎אהבה‎, his love for people. This ‎attribute included even in their concerns with matters that did ‎not involve their relations to the Creator. This being so, G’d did ‎not object to his descending to Egypt, leaving the soil of the Holy ‎Land. His son Yitzchok’s primary attribute was ‎יראה‎, reverence ‎for the Essence of G’d; i.e. he concentrated all his faculties on how ‎to serve G’d. This being so, it would have interfered with his basic ‎character were he to leave the sacred soil of the land of Israel for ‎even a short period.‎