長阿含經 30.p24

30.p24

“The god Māra’s palace is halfway between the Paranirmitavaśavartin Heaven and the Brahmakāyika Heaven. It’s 6,000 yojanas in diameter and has seven fortress walls made of treasures, seven balustrades, seven nettings, and seven rows of trees … Countless birds of many kinds sing peacefully to each other as before.