 लक्ष्यालक्ष्येण रूपेण रात्रौ लङ्का पुरी मया।प्रवेष्टुं प्राप्तकालं मे कृत्यं साधयितुं महत्।। 
 To accomplish this great task I will have to assume an inconspicious form and enter the city of Lanka in the night as that is the appropriate time. 