Shiva Purana
आसीन्मूत्रोत्सर्गकामो मार्गे हि शिवमायया॥ तत्स्तंभितुं न शक्तोभूत्पौलस्त्यो रावणः प्रभुः॥ १७॥
Thanks to Śiva’s Māyā, he became desirous of passing urine while yet on his way. Lord Rāvaṇa of the family of Pulastya could not stop this urge.
english translation
AsInmUtrotsargakAmo mArge hi zivamAyayA॥ tatstaMbhituM na zaktobhUtpaulastyo rAvaNaH prabhuH॥ 17॥
hk transliteration by Sanscript