In Vaetchanan, the Torah records the first Parashah of the Shema prayer. One of the many differences between this Parashah and the second Parashah in Parashat Eikev is that the former is presented in the singular form, whereas the latter is presented in the plural. What is the reason for this discrepancy?
To answer this question, let us analyze a few other areas of Torah. Why did Hashem create Adam before Chavah if he knew he would create her later that day? Perhaps Hashem did so to stress that each person has to have his own relationship with Hashem. By creating Adam separate from his wife, Hashem shows that every person must have his own relationship with Him, independent of the connection that Hashem has with mankind as a whole. (For alternate explanations, see Sanhedrin 37a, 38a.)
A similar idea is expressed by the Vilna Gaon, who explains “VeHayu HaDevarim HaEileh Asher Anochi Metzavecha HaYom Al Levavecha,” “And these words that I command you today shall be upon your heart” (Devarim 6:6) as a message regarding Torah learning. “And these words… shall be upon your heart” teaches us that when one learns, he should not worry about what other areas of Torah he has yet to learn, but rather simply focus on what is in front of him. “That I command you” teaches us that one must feel that he is the only person being commanded the Mitzvah of Talmud Torah; it is a personalized task from Hashem for him. “Today” means that one should view every day as the last day of the world’s existence, so he cannot push off his learning to another day. The Vilna Gaon stresses the importance for the individual to view his commandment to connect to Hashem through Torah learning as something given only to him, not to anyone else.
Similarly, the beginning of Shemoneh Esreih, which reads “Blessed are you Hashem, Our God and the God of our fathers,” expresses a similar idea. Why do we begin by stating that Hashem is our God and only afterwards stating that He is our fathers’ God? If our fathers preceded us and discovered Hashem before us, should we not mention them first? The Anshei Kenesset HaGedolah, the authors of the Shemoneh Esreih, stressed that each person has to recognize God on his own. One must not declare God’s existence simply because of a tradition from his parents; rather, he must also do so out of his own common sense and volition.
With these three ideas in mind, we can answer why the first paragraph is written in singular. When addressing the commandment to accept heaven’s yoke, the purpose of reciting the first paragraph daily (Berachot 13a), Hashem wants to remind us that we should not accept His sovereignty simply because it is something passed down from generation to generation of Klal Yisroel; rather, every individual must accept this fact, and ultimately view his entire Avodat Hashem, as something personally assigned to him from Hashem.