The most direct testimony to the sources of Rav Kook's thought comes from his own pen: in Otzrot HaRaayah, Vol. 6, Part ב 103:3, he states explicitly that everything in his writings was drawn not from his own mind but from the foundations of the words of Chazal and true Kabbalah, and that one who cleaves to them with study, review, and purity of heart is fortunate.
The Otzrot HaRaayah manuscripts confirm two further dimensions of this project: Otzrot HaRaayah, Vol. 6, Part א 37:16 preserves writings from Rav Kook's holy hand on the necessity of exalted awareness in Torah and mitzvot, and Otzrot HaRaayah, Vol. 6, Part ב 105:1 contains a treatise on the study of the spirituality of Torah, presented as a supplement to Orot HaTorah — together showing how his later published works grew from ongoing private manuscript reflection.
The Rishonim supplied foundational conceptual building-blocks: the Ramban (Vayikra 18:25) articulates the unique metaphysical status of Eretz Yisrael as the direct inheritance of God, administered by no angelic intermediary, and the Ramban (Bereishit 12:6) establishes the principle that the deeds of the Patriarchs are signs for the children — both ideas that animate Rav Kook's teaching on the land and national destiny as developed in Orot, Lights from Darkness, Land of Israel 1:2, where he insists that the inner sanctity of Eretz Yisrael cannot be grasped by rational intellect alone but only through the spirit of God resting upon the nation as a whole.
The Kuzari's framework of Israel's unique spiritual faculty — articulated in Kuzari 1:35-43, where the Haver distinguishes the rational order common to all humanity from the higher ordering that governs Israel — anticipates Rav Kook's vision in Orot, Lights from Darkness, Israel and its Rebirth 1, where he describes Israel's knowledge of God as woven into the nation's innermost nature, its history of survival against enemies, and the very texture of its poetry and moral life.
The Hasidic tradition, particularly the Tanya and Rebbe Nachman, furnished Rav Kook with the language of divine contraction, the elevation of darkness to light, and the power of faith over philosophical uncertainty: Tanya, Part I; Likkutei Amarim 36 teaches that God desired an abode in the lower worlds and that satisfaction comes when the sitra achara is subdued and darkness turns to light, Tanya, Part I; Likkutei Amarim 49 grounds this in the purpose of all the tzimtzumim being the elevation of the entire human person to God, and Likutei Moharan 64 holds that through pure faith Israel prevails over all philosophical questions that arise from the Vacated Space — themes that resonate throughout Rav Kook's treatment of teshuvah in Orot HaTeshuvah, where intellectual repentance crowns the natural and faith-based stages by transforming sins into merits and every failure into a sublime ascent.
The Maharal's writings provided another deep stratum: Tiferet Yisrael 16 argues that the Torah given to Klal Yisrael as a whole represents the perfection of the collective intellect, while Tiferet Yisrael 1:6 identifies the mitzvot as the actions uniquely suited to the human being by virtue of the divine soul — both ideas echoed in Orot HaKodesh 1:1:1, where Rav Kook distinguishes sacred wisdom from all secular knowledge precisely because sacred wisdom transforms the very character and will of those who study it, drawing their inner being toward the exaltedness it inhabits, given that all sacred matters flow from the source of life that has the power to create worlds.
Netzach Yisrael 1:1 of the Maharal argues that true knowledge of any good is acquired only from its opposite, and that the Haggadah therefore begins with disgrace in order to arrive at genuine praise — a dialectical structure also operative in Orot HaKodesh 3:1:1, where Rav Kook declares that Israel's supreme moral teaching must extend over all existence and is compelled by that very scope to be of heavenly origin, reflecting the same movement from the lowly and bounded toward the unlimited divine good.
The Gemara in Sanhedrin 98a-99a records the tension between "in its time" and "I will hasten it" regarding the redemption — if Israel merits, God hastens; if not, the appointed time stands — and this Talmudic dialectic between historical necessity and moral agency supplies the structural backbone of Kol HaTor 1:1 (the Gaon of Vilna's teachings on the beginning of the redemption), which Rav Kook drew upon for his understanding of the footsteps of the Messiah and active participation in the unfolding of geulah.
Ein Aya, Shabbat 5:34 — Rav Kook's own early commentary on the Aggadah — shows the earlier strata of his thought directly: there he teaches that one who has truly attained the understanding of Torah knows its purpose as a whole and uses every commandment and intention the way letters are used to express limitless thoughts, so that the Torah constantly generates new articulations, citing the verse "for Your testimonies are my conversation" — revealing how his mature mystical syntheses in Orot HaKodesh were already being formed through close engagement with the Talmudic text.