Shiva Purana
तदा च गिरिजादेवी विरहं पुत्रसंभवम् ॥ शंभुश्च परमं दुःखं प्राप तस्मिन्ननागते ॥ १३ ॥
When he did not return, goddess Pārvatī felt severely the pangs of separation from her son. Śiva too was extremely miserable.
english translation
tadA ca girijAdevI virahaM putrasaMbhavam ॥ zaMbhuzca paramaM duHkhaM prApa tasminnanAgate ॥ 13 ॥
hk transliteration by Sanscript