淨土五會念佛誦經觀行儀卷中．下 2.5

2.5

又舍利弗。極樂國土。七重欄楯。七重羅網。七重行樹。皆是四寶周匝圍繞。是故彼國。名曰極樂。

"Moreover, Śāriputra, the land of Sukhāvatī is completely encircled with seven tiers of railings, seven tiers of nets, and seven tiers of rows of trees, all made of the four jewels. For this reason, that land is named Sukhāvatī.