Ramayana
यूयमेवाभिजानीत योऽयं यद्वा करिष्यति । अहिरेव ह्यहेः पादान्विजानाति न संशयः ॥ ५-४२-९
'You alone can know about who he is and what he is about. A serpent alone knows the movement (footprints) of another serpent. There is no doubt about it. ॥ 5-42-9॥
english translation
yUyamevAbhijAnIta yo'yaM yadvA kariSyati । ahireva hyaheH pAdAnvijAnAti na saMzayaH ॥ 5-42-9
hk transliteration by Sanscript