Shiva Purana
वेदिका तु महाविद्या लिंगं देवो महेश्वरः । अतो हि स्थावरे लिंगे स्मृता श्रेष्ठादिखंडिता ३१ ।
The pedestal is the great Māyā; the phallic image is lord Śiva. Hence in immobile image two-piece construction is recommended.
english translation
vedikA tu mahAvidyA liMgaM devo mahezvaraH । ato hi sthAvare liMge smRtA zreSThAdikhaMDitA 31 ।
hk transliteration by Sanscript