Dor is "generation" in Hebrew. It is related to the word kadur (ball) and therefore implies a cyclical perception of generations rising and passing away. As Kohelet proclaims, "One dor goes; another dor comes." (Ecclesiastes 1:4).
Psalm 24 asks, "Who may ascend the mountain of the Lord?": after listing some lofty attributes ("he who has clean hands"), it concludes, "such is the dor of those who turn to Him." Here, dor means a cadre of worthies, a closed circle and not the entire generation.
The eternity of God's covenant with Israel often appears as "dor vador". "The Lord is good… His faithfulness is for dor vador" (Psalm 100:5). We reciprocate God's eternal commitment by praise throughout the generations. Dor l'dor Your works will be lauded"(Psalm 145:4).
The consonance of dor vador gives emphasis to the idea of the interconnectedness of each generation in the inexorable march of time.
Will our dor be more than just a passing age (a la Kohelet) or a small cadre of elites, or will its members feel bound to each other with a message to pass down to the next dor? That is the challenge of the leaders of every dor of the Jewish nation.