שְׁמַ֖ע יִשְׂרָאֵ֑ל יְהוָ֥ה אֱלֹהֵ֖ינוּ יְהוָ֥ה ׀ אֶחָֽד׃
הער, ישׂראל: ה׳ אונדזער גאָט, ה׳ איז אײנער.
Netivot Olam
However it appears from the words of the sages that the love that a person has for his Creator is from another angle. And that is that which they said in the chapter [entitled] HaRoeh (Berakhot 61b), "When they took Rabbi Akiva out to be executed, it was time for the recitation of Shema. And they were raking his flesh with iron combs, and he intended to accept upon himself the yoke of Heaven [by reciting Shema]. His students said to him, 'Our teacher, even now?' He said to them, 'All my days I have been troubled by the verse, with all your soul (Deuteronomy 6:5), [meaning] even if God takes your soul. I said, "When will it come to me to fulfill it?" Now that it has come to me, shall I not fulfill it?' He prolonged [the word], One until his soul departed with One. A voice descended from heaven and said, 'Happy are you, Rabbi Akiva, that your soul left with One.'" But now it will be difficult to you: How did Rabbi Akiva fulfill loving God, may He be blessed, with all of his heart and all of his soul through that which he prolonged, One, until his soul departed with One? However, this thing is because the love that a person has towards God, may He be blessed, is from that which a person is nothing from the angle of himself, but rather is only coming from God, may He be blessed, and returns to Him, since everything returns to Him, may He blessed, and there is nothing besides God, may He be blessed. So He is One, and there is nothing besides Him. And hence they, may their memory be blessed, said (Berakhot 4b-5a), "Even though one recited Shema in the synagogue, he must also recite the Shema upon his bed. [...] But if one is a Torah scholar, he need not [recite it. Nevertheless] he must recite at least one verse of prayer, [such as,] Into Your hand I deposit my spirit (Psalms 31:6)." Yet it is implied that if one recites Shema — meaning, Listen Israel, the Lord is our God, the Lord is One — he does not have to say, Into Your hand I deposit my spirit. But when did he say, Into Your hand I deposit my spirit? However, it is this thing — that he said, the Lord is One, that He, may He be blessed, is One, and there is none besides Him. And from the angle that He, may He be blessed, is One, and there is none besides Him, everything returns to Him. And through this, His soul returns to God, may He be blessed. So [through this] he deposits his soul in God's hands, may He be blessed. And that is why Rabbi Akiva prolonged One until his soul departed. As it is because He, may He be blessed, is One, that the soul returns to Him, may He be blessed. So when he prolonged One until his soul departed, his soul completely returned to God, may He be blessed, in that He is One. And it is from this angle that love is found. And that is why it stated, the Lord is our God, the Lord is One. And you shall love the Lord your God, etc. (Deuteronomy 6:4-5). Since from the angle that He, may He be blessed, is One, there is nothing in existence in the world that is separate from Him, as everything is dependent upon, and clinging to, Him, may He be blessed. For He, may He be blessed, is the essence of everything. And that is why love is fitting towards God, may He be blessed; and love is more fitting towards God, may He be blessed, than love with other things. For even if they cling to one another, any love that there is between lovers is nevertheless [attenuated by there being] a separate existence to each one. But with the love of God, may He be blessed, it is [otherwise,] since a person completely returns his spirit and his soul to Him to the point that there is no individual existence for the person, and he is thereby completely clinging to Him. This is as it is written, to love the Lord your God and to cling to Him (Deuteronomy 11:22). So because of this, complete love is fitting. And it is like Rabbi Akiva said, "All my days I have been troubled by the verse, And you shall love the Lord your God with all your heart, with all your soul (Deuteronomy 6:5). Now that it has come to me, shall I not fulfill it?" For this is complete love; when one gives up his life to the Lord. As with this, he clings to Him completely. And that is the essence of love. So it has been clarified to you that love is more fitting towards God, may He be blessed, in that man gives up his life to God, may He be blessed, and completely clings to Him. And that is true love.
Akeidat Yitzchak
The Midrash Tanchuma on Parshat Vayechi states that Jacob was prevented from disclosing part of the future to his sons, because when he called them in he failed to call on G-d’s Presence at the same time. A trusted servant who had the complete run of the king's household once determined to give his sons the status of free men and to tell them where the documents confirming this status could be obtained. The king, divining the servant's intention, positioned himself above the servant. Thereupon, the servant, fearful of being caught in an act of disloyalty, began to exhort his sons to promise continued loyal service to the king. Similarly, Jacob called in his sons to tell them about the time their exile would come to an end. Immediately, G-d appeared, wanting to know, "Why have you invited them without inviting Me?" This is the meaning of Isaiah 43,22, "And Me you have not called, Jacob!" As soon as Jacob realized this, he began to tell his sons that they should declare that they would serve the Lord just as their fathers had done, i.e. "the Lord before whom my fathers have walked" (48,15). The sons responded saying, "We know what is in your heart. As you are true to only one Master, so we too will serve only one Master" (shema yisrael). When Jacob heard this, he responded by saying, "Blessed be the name of His glorious Majesty, forever."
Akeidat Yitzchak
Because prayer is service of the heart, we have connected the chapter on prayer with the chapter on the olah, total offering. As an olah is an offering that "rises" towards G'd in its entirety, since the whole of the animal is being offered on the altar, so is prayer an offering of the heart which rises toward Heaven in its entirety. When our sages describe prayer without concentrating on its meaning, as being comparable to a body without soul, they mean that the warmth of feeling generated by genuine prayer, parallels the ongoing fire on the altar that burns the olah. In Vayikra Rabbah 7, Rabbi Pinchas notes that the Torah does not describe the fire on the altar as being "on" the altar. The Torah does not require that the "fire on the altar burn on it," rather it does say “aysh hamizbeach tukad bo," the fire on the altar shall burn within it, meaning that the entire altar should be permeated by it. (Leviticus 6,2) So our hearts are to be permeated by the outpouring of our prayers. The Talmud Berachot 32, tells us that we have to arrange the praise of the Lord before proceeding with voicing our requests from Him. Since the requests concern mostly our temporal needs, our sages (Shabbat 10) describe the supplicant as someone who temporarily abandons his concern with the values of the world to come, in favour of the mundane needs of this world he lives in at the time. If this is so, the opinion held by many, (including Maimonides chapter one hilchot tefillah ) which claims that prayer has been legislated by the Torah, is hard to understand. If the purpose of prayer would be exhausted by our asking for our needs, why should it matter to G'd whether we ask for them or not? We should be entitled to forego the opportunity to ask G'd for His kindness, assistance, etc. However, just as we have described the institution of sacrifice as designed to arouse certain emotions within us which will bring us closer to G'd, so prayer, by means of the trust we express when we ask Him for our needs, will bring us closer to Him. The conviction that He cares, that His Providence watches over us, all this helps to strengthen the existing ties between us and the Creator. The thanks we express for what He has done for us and for others, all help to cement our relationship with hashem. The early Chassidim, men of piety and devoutness, are described by the Talmud Berachot 32, as having prepared for prayer an hour ahead of time, and as having spent another hour winding down from the spiritual high achieved during prayer, before returning to the mundane tasks in their lives. Actually, they did exactly what our sages have since built into the formal liturgy that we follow nowadays. The hymns of praise, keriyat shema, are our introduction and preparation for prayer, i.e. the part during which we voice our requests. On the other hand, we are told that he who fails to enunciate the keriyat shema audibly, has failed in his purpose, since the praise of G'd and our assuming the yoke of Heaven are to be made known to our fellow men. On the other hand, he who raises his voice during the supplication part of the prayer service, is described as lacking in faith, as a prophet of the ido Baal. (Berachot 24) Channah already demonstrated that requests need not be aired audibly. If the High Priest Eli considered her as a drunken woman, this was not because she did not raise her voice in prayer, but because she had chosen a time of day he did not consider suitable for offering up prayer. (compare Samuel I chapter 1) He watched her closely to find out what she had to say to him, since most other women milling around the entrance of the tabernacle always spoke to him. Understanding Eli's error, she told him that her remarks were addressed to Him who does not need audible expression of her words in order to be able to hear and understand them. Since Channah came to the tabernacle after having dined, it was natural for Eli to have misconstrued her purpose, and to have judged same by outward appearances. In fact, one must not raise one's voice, so as not to create the impression that one considers G'd hard of hearing. When Ishmael was close to death, (Genesis 21,17) G'd considered his state of being "as he was then," not the loudness of his prayers. The mental anguish that he was suffering at that moment was the decisive element that led to his rescue. On the other hand, all those paragraphs in the liturgy that teach us knowledge and comprehension have to be recited aloud. "Hear O Israel!"- these words we have to hear with our own ears; they are directed both at ourselves and at our fellow Jews.