“Listen O heavens, and I will speak, and the earth shall hear the words of my mouth…” (Deut. 32:1). These are the opening words of a poetic song uttered by Moshe shortly before his demise. In this passage the word for “listen” is ha’azinu, while the word for “hear” is tishma. A form of the latter word is more famously used in the formula “Hear (Shema) O Israel, Hashem our G-d — Hashem is one” (Deut. 6:4). While some Tosafists actually write that the two words are used interchangeably for poetic effect, most commentators reject the concept of synonyms in the Holy Language, and must therefore explain the words thusly. So, what is the difference between the word shema and ha’azinu? Furthermore, while Moshe uses ha’azinu for the heavens and shema for the earth, the prophet Yishaya uses the exact opposite formulation: “Hear O heavens, and listen O earth, for G-d has spoken” (Isa. 1:2). In this context, Yishaya uses ha’azinu for the earth, and shema for the heavens. Why does Yishaya deviate from the norm already established by Moshe?
The Midrash (Sifri to Parshat Ha’azinu) explains that these two terms reflect two types of listening. One type of listening refers to hearing something from afar, while the other type of listening refers to hearing something nearby. When one listens to something from a distance he must be especially attentive to the sound in order to properly concentrate, hear what should be heard, and focus on its meaning. According to the Midrash, shema refers to listening from a distance, while ha’azinu refers to listening from close-range. (Other commentators, such as Chizkuni, Abarbanel, and Rabbi Yitzchak Arama, disagree with the Midrash and actually define the terms in the opposite way, and explain the difference between Moshe and Yishaya accordingly.)
Based on this, the Midrash explains that Moshe was closer to the heavens, so he used ha’azinu to refer to the heavens listening to him, while he was farther from the earth, so he used shema when referring to the earth listening to him. Conversely, Yishaya was closer to the earth, so he used ha’azinu for the earth, and only used shema for the heavens.
However, this explanation begs the question: Since both Moshe and Yishaya were prophets of G-d, then why is Moshe considered “closer to the heavens” and Yishaya considered “closer to the earth”? The commentators offer several ways of differentiating between Moshe and Yishaya in this context. The first answer argues that because Moshe pronounced his epic song in the days before his death, he was considered “closer to the heavens” simply because his death was approaching and he already had “one foot” in the heavens; whereas the passage from Yishaya was at the start of his prophetic career, well before his death.
The second answer explains that although Moshe and Yishaya were two of the most important prophets, the importance of Moshe infinitely exceeds that of Yishaya. Moshe was the “father of all prophets”, and attained a level of clarity in his prophecy unrivaled by any other prophet. As G-d Himself said of Moshe, “Mouth to mouth I speak to him, in a clear vision, and not in riddles…” (Num. 12:8). While Yishaya’s prophecies served to uphold the Torah, only Moshe’s prophecies became the Torah itself. For this reason Moshe’s elevated spiritual existence rendered him closer to the heavens than to the earth. In contrast, Yishaya, for all that he continuously rebuked the Jewish People to keep the Torah, remained closer to the earth like an ordinary human being. Similarly, a third answer suggests that since Moshe was accustomed to ascending to the heavens, as he ascended Mount Sinai multiple times for long stretches, he is considered “closer to the heavens” than anyone else.
Other sources point to another distinction between the words ha’azinu and shema. The word ha’azinu is derived from the Hebrew word ozen, which means ear. As such, the verb of listening expressed by the word ha’azinu refers simply to the physiological function of the ear: hearing sound waves and relaying them to the brain. On the other hand, explains the Malbim, the word shema does not refer simply to the physical act of listening; rather it also denotes a certain degree of intellectual or emotional understanding of that which is being heard.
Rokeach explains that the word shema refers to hearkening in response to another’s call, while ha’azinu simplyrefers to any type of listening. However, these explanations fail to account for the change in phraseology between the introduction of Moshe’s song and Yishaya’s opening prophecy. Elsewhere, Rokeach writes that shema refers to listening to something which was stated explicitly, while ha’azinu refers to listening and inferring to something only said implicitly.