Hekhalot Rabbati, as a "macroform," is a fairly difficult work, evincing a great deal of internal literary disparities and lengthy additions in some mss. (esp. N8128). It contains several different genres of material: ascents or "descents" to the merkavah (chariot throne) of God in the heavenly courtroom, liturgies (to ascend/descend and participate in while in the heavenly courtroom), apocalypses, Sar Torah (adjuration of an angel), and lore concerning mystically oriented Rabbis. While Gershom Scholem considered it one of the latest of the Hekhalot texts (among which also include: Hekhalot Zutarti, Ma'aseh Merkavah, Merkavah Rabbah, and Sefer Hekhalot / 3 Enoch), Peter Schäfer argues it is the earliest. The overall dating, social location, etc., of the Hekhalot texts in general has been debated with little consensus. They likely contain traditions going back to the Tannaitic period, but in their current "macroforms" they are probably para- or post-Talmudic with ongoing revision and editorial activity occurring well into the Middle Ages.
I am starting with a fairly simple pericope to encourage others with access to a copy of the Synopose to join in. I will also keep the pericopes short (so today I am only doing half a pericope). I will, unfortunately, have to do this sporadically due to my schedule restrictions. So, here goes:
אמר רבי ישמאל מה אילו שירות שהיה אומר מי שמבקש להסתכל בצפיית המרכבה לירד בשלום ולעלות בשלום
Rabbi Ishmael said: What are the songs he would recite who seeks to behold a vision of the merkavah, to descend in peace and to ascend in peace?
Some notes on the text: some mss. use נאמר rather than אומר (M40), some omit the definite article before the word מרכבה (N8128, O1531) and some add הן between אילו and מה (M40, D436).
These are supposedly the first lines of Hekhalot Rabbati. They indicate one of the most important aspects of the literature: the incorporation of elaborate and lengthy liturgical pieces that are necessary to ascend/descend to the chariot and that are sung in the divine presence. In fact, it is primarily from the contents of the liturgies that one discovers much of the perspective (or perspectives) concerning the characteristics of God, the angels, and humans (particularly Israel) and the relationships with one another. R. Ishmael's question indicates that these songs--note they are "recited" rather than "sung," per se--are the means to see God. The "descent in peace and ascend in peace" resembles the Rabbinic tradition of the four who entered pardes (see, e.g., B. Hag. 14b); only Rabbi Akiva--a hero in the Hekhalot texts--entered and exited peacefully.
Taking a look at the verbs. Some of the translations I have seen omit translating the participle "seeking/desiring." Yet I think it adds something to the sentence--it denotes that the learning, preparation, and execution of descending to the chariot to have a vision of it is a process; it is a quest.
In terms of "behold," the Hekhalot texts use several different verbs of seeing, beholding, gazing, glimpsing. Although there is a great deal of auditory emphasis in the texts (hearing the divine liturgy) they are also highly visually oriented.
Finally, the order of "descend" and "ascend." The Hekhalot texts have drawn a great deal of commentary on the unexpected language of "descending" to the merkavah rather than the expected "ascending." That is one "descends" to heaven and then "ascends" back to earth. Elliot Wolfson argues that the language refers to only the last leg of the journey: one "ascends" the entire way and then in the seventh heaven "descends" to the merkavah, being enthroned oneself. Alan Segal suggested it might relate to the "posture of Elijah"; that is, one is placing one's head between one's knees to inculcate the altered state of consciousness that would allow one to see a vision--so it has to do with mystical practice. Others just find it paradoxical and leave it at that. Nonetheless, I personally have not found any of the explanations I have read to be convincing.
I would add one more comment on the "in peace." The rest of Hekhalot Rabbati demonstrates the dangers, difficulties, and apparent impossibilities of this quest--with angels throwing metal rods at you, the voice of the cherubim killing you, and the sight of God's Beauty destroying all creatures, angelic or human--yet different Rabbis (R. Ishmael, R. Akiva, and R. Nehuniah b. Ha-Kanah) will discuss how to overcome these difficulties so that one can descend/ascend at will, see the enthroned God, and participate in the heavenly courtly activities (and, most importantly, report back to Israel what is going on up there!).