In the 890th sūtra of the Saṃyuktāgama, at the end of the sūtra, the text transmits a number of metaphors, such as "the deathless" (不死) and "the island" (洲渚). One of these terms is "流通" which appears to mean "to circulate, to propagate, to distribute, to pass down," but seems to be being used as a noun. What does it mean in this context?
Full text of section:
如無為，如是難見、不動、不屈、不死、無漏、覆 蔭、洲渚、濟渡、依止、擁護、不流轉、離熾焰、離 燒然、流通、清涼、微妙、安隱、無病、無所有、 涅槃，亦如是說。
As a further question, what is the fine difference between introducing the first element of the list with just "如" and the second element with "如是?"
Thank you for your time, all.