Agnipurana 78.14

78.14

kāryā vā candravahnyarkapavitraṃ(1) śivavaddhṛdi /
ekaikaṃ nijamūrtau vā puptake guruke gaṇe(2) //

Or the sacred threads of the Moon, Fire, and Sun should be made on the chest, like Śiva's,
or one on each own icon, on the sacred book, on the guru, and on the assembly;