Ramayana
पूर्वमेतत्कृतं द्वारं पृथिव्या भुवनस्य च । सूर्यस्योदयनं चैव पर्वा ह्येषा दिगुच्यते ॥ ४-४०-६३
'Here is the entrance for the earth as well as for all the worlds and since the Sun also rises from this place it is called the eastern direction. ॥ 4-40-63॥
english translation
pUrvametatkRtaM dvAraM pRthivyA bhuvanasya ca । sUryasyodayanaM caiva parvA hyeSA digucyate ॥ 4-40-63
hk transliteration by Sanscript