Shiva Purana
शंखकुंदेंदुधवलं संध्याख्यं सौम्यलक्षणम् ॥ शिवस्य पश्चिमं वक्त्रं शिवपादार्चने रतम् ॥ ३९ ॥
The conchshell, lotus flower and milk are known as sandhya and are gentle. The western face of Lord Shiva is engaged in worshiping the feet of Lord Shiva.
english translation
zaMkhakuMdeMdudhavalaM saMdhyAkhyaM saumyalakSaNam ॥ zivasya pazcimaM vaktraM zivapAdArcane ratam ॥ 39 ॥
hk transliteration by Sanscript