Likutei Moharan 58:2/ליקוטי מוהר"ן נ״ח:ב׳

12. Moshe’s soul embodied the three Patriarchs. He thus had the power to draw these three influxes. The “well of living water” (Genesis 26:19) is the aspect of Avraham, [the aspect of] the waters of lovingkindness; and Avraham began to dig wells. The cloud is the aspect of Yitzchak, the aspect of “darkness, cloud and mist” (Deuteronomy 4:11) ; the aspect of “[Yitzchak’s] eyes grew dim and he could not see” (Genesis 27:1). And manna is the aspect of Yaakov, the aspect of “to nourish His people, Yaakov” (Psalms 78:71) .

2Thus of Moshe, who embodied the Patriarchs, it is said, “Moshe sat down beside the well” (Exodus 2:15) ; and it is written of him, “Moshe entered within the cloud” (ibid. 24:18) ; and it is likewise written of him, “Moshe said to them, ‘This is the bread’” (ibid. 16:15). Specifically “this,” referring to Moshe himself, because it was in his merit that they ate the manna.

3And in the Future, at the time of the resurrection, Moshe will arise embodying the three Patriarchs as before, in the aspect of “That which was, is what will be” (Ecclesiastes 1:9) ; the aspect of “See, you will lie with your fathers, and then rise up” (Deuteronomy 31:16)—he will be resurrected embodying the three of them. This is the explanation of “one is maintained by three.”