Arthashastra
तीक्ष्णम् उत्साहिनं व्यसनिनं स्थित शत्रुं वा गूढ पुरुषाः शस्त्र अग्नि रस आदिभिः साधयेयुः, सौकर्यतो वा तेषाम् अन्यतमः ॥
Spies under concealment may, without the help of a fiery spy, murder by means of weapons, poison or other things a fortified enemy who is of mean character or who is under troubles; any one of hidden spies may do the work when it is found easy.
english translation
tIkSNam utsAhinaM vyasaninaM sthita zatruM vA gUDha puruSAH zastra agni rasa AdibhiH sAdhayeyuH, saukaryato vA teSAm anyatamaH ॥
hk transliteration by Sanscript