The phrase "谢天谢地" is formed through a parallel and repetitive structure that combines two elemental and universal forces, "天" (heaven/sky) and "地" (earth/land), each preceded by the verb "谢" (to thank). This doubling creates a sense of completeness and emphasis, symbolically expressing gratitude to the entire cosmos or all conceivable higher powers. It evokes the imagery of a person looking upwards to the heavens and downwards to the earth in profound relief or thankfulness, thereby capturing a holistic and deeply felt sentiment through its symmetrical and all-encompassing formulation.