Yitzchak Avinu is perhaps the most facinating of our three Avos. While we know are great deal about the deeds and adventures of Avraham Avinu and Yaakov Avinu, Yitzchak seems to get comparatively little time in the narrative of Bereishis. Further, the little "face time" he does get in parsha Toldos is quite uninspiring. He prays for and gets kids, goes to live amongst the Pelishtim for a short time and gets into trouble with them and then blesses his sons when he gets old. That's about it for his active participation in the history of our people.
Yet if one look scarefully through the Chumash, Yiztchak actually appears in as many parashas as his father and son. Avraham appears in three (Lech Lecha, Vayera, Chayei Sarah). Yaakov stars in (Toldos, Vayetzei, Vayishlah, as well as cameos in Vayeshev, Miketz and Vayechi). Yitzchak, however, plays important roles not just in Toldos but also Vayera and Chayei Sarah. Why then the perception that he only really shows up briefly?
Every day of the week, when reciting Uva L'Tzion, we recite the following words:
"Holy, holy, holy is the Lord of Hosts, the entire world is filled with His glory. And they receive from one another and say: Holy in the highest Heavens, the place of his Divine Presence, holy on the Earth, the work of His mightiness, holy for ever and ever."
(Blue=original Hebrew verse; Orange=Aramaic interpretative translation)
Rav Tzi Yehudah Kook, zt"l, notes that the Targum of the Biblical verse tells us that holiness originally resides in Heaven with God as its source. By leaving a life in accordance with Torah and striving towards personal and national holiness, we draw that Divine energy down towards us, as the verse tells us: Thou shalt be holy for I the Lord thine God am holy." (Vayikra 19:2) Having achieved a drawing of the Divine holiness down into this world, we then bask in the eternal spiritual purity it provides, hence the third part of the Targum's interpretation.
Rav Kook then analyzes Avraham and Yitzchak and notes their respective parts in this process. Avraham, it is clearly, was active in drawing Divine holiness down to this world through his constant efforts to make the presence of God obvious to all those around him. Yitzchak, however, played a more passive role. He let the Akeidah happen to him. He let Eliezer bring his wife to him. Even when he could have been active in deciding who to give his paternal brachah to at the end of his life, that choice was made by Rivkah Imeinu and Yaakov. Yet all is not what it seems. Yitzchak was not simply a sounding board, a passive target for the activity of others. Rather, with Avraham having done the work of bringing God's holiness into this world, Yitzchak immersed himself in it and spent his life basking in that spiritual ectasy and the unprecedented connection to the Divine that came with it.
One might think, therefore, that Yitzchak had the easier job. Yet Rav Kook says that it is just the opposite. Activity is easy. One is striving for a goal, building towards it, always having a focus for one's energy. Maintaining oneself at a spiritual peak, spending all one's days at the highest level of purity, is far harder because of the danger of slipping that is constantly present. A simple questioning at the time when his father was putting him on the altar, an insistence on having an active role in choosing his wife instead of letting the Hand of God decide events, a demand for photograph ID when Yaakov presented himself for the brachah, all this seemingly minor activities which also appear emminently reasonable, would have taken him away from the peak of holiness in which he dwelt.
The Gemara in Zevachim, 62a, discusses how the Jews who returned from Bavel and wanted to rebuild the Temple determined the original position of the external altar so they could put a new one there:
"It is understood that the form of the Temple could be recognized (Rashi: the Anshei Knesses HaGedolah knew where the Kodesh, Heichal and courtyard were). But how did they know where the altar had been? Rabbi Elazar said: 'They saw a vision of an built alter and the great minister Micha'el standing and offering upon it.' Rabbi Yitzchak Napachah said 'They saw the ashes of Yitzchak piled up in that place.' Rabbi Shmuel bar Nachmani said 'The whole Temple are smelled of the incense but that place smelled of the limbs of the sacrifices.'"
What is the significance of these three visions? In the context of the three levels of "kadosh" above and the difference between being active and passive as noted by Rav Kook, I would suggest the following. The first vision, that of an altar in use with Micha'el offering the souls of the righteous, was indicative of the first level of holiness, that of the Divine. It is also indicative of the active pursuit of holiness. Offering a sacrifice requires a person to take action, after all, and make the offering in both the physical and spiritual sense of the word. The second vision, that of the ashes of Yitzchak, represents the second level of holiness, that which is brought into this world. It is also demonstrative of the passive since Yitzchak's participation in that event was entirely passive. Ashes are entirely physical, the remnant of the sacrifice from which the spiritual has ascended to Father in Heaven. They also represent the effort of he who brought the offering and who passively accepted God's judgement upon himself.
The final vision, that of the two smells, represents the final level of holiness, which is eternal. The uniqueness of the k'tores in the Temple service is that it was the most spiritual and least physical of all the offerings. Some spices were put on the golden alter within the Heichal and it was the scent which became the offering. Not the smoke, not the residence, but the emphemeral, invisible scent. Corresponding to this was the scent of the limbs of the sacrifice, the constantly mentioned re'ach nicho'ach in the Torah which was, despite its obvious presence, also invisible. When experiencing this vision, the Jews of the time were therefore given a vision of basking in the eternal holiness that comes when they bring the Divine back into this world. These three visions therefore replicated the efforts of both Avraham and Yitzchak to bring the Divine back into this world and allow us to immerse ourselves in it and raise ourselves to the highest possible levels of Avodas HaShem, the level in which we reach our highest level of potential through our passivity.