Shiva Purana
शिवलिंगं शिवं मत्वा स्वात्मानं शक्तिरूपकम् । शक्तिलिंगं च देवीं च मत्वा स्वं शिवरूपकम् १३७ ।
One should regard the Shiva Lingam as Shiva itself and perceive one's own soul as the embodiment of Shakti (divine power). Likewise, one should view the Shakti Lingam as the Goddess and recognize one's own self as Shiva.
english translation
zivaliMgaM zivaM matvA svAtmAnaM zaktirUpakam । zaktiliMgaM ca devIM ca matvA svaM zivarUpakam 137 ।
hk transliteration by Sanscript