The rainbow symbolizes connection...connection to the unseen realms. In Hawaiian belief, rainbows are actually a full circle. The other half of the rainbow is underground. In our world, where only half the picture is visible, there is always a hidden side to things. The same goes for ourselves. We have the mind, which uses words, and then we have the heart which goes far beyond words. We have the outer appearance of us, and then we have our spirit.
なるかみの, すこしとよみて, A faint clap of thunder, さしくもり, Clouded skies, あめもふらぬか, Perhaps rain will come. きみをとどめむ? If so, will you stay here with me? なるかみの, すこしとよみて, A faint clap of thunder, ふらずとも, Even if rain comes or not, わはとどまらむ, I will stay here, いもしとどめば。 Together with you. 万葉集 11, 2514 - 2513 (Man’yōshū vol. 11, verse 2514 - 2513), 言の葉の庭 (The Garden of Words).