Arthashastra
लुब्धक व्यञ्जना वा व्याल मृगान् पञ्जरेभ्यः प्रमुञ्चेयुः, सर्प ग्राहा वा सर्पान् उग्र विषान्, हस्ति जीविनो वा हस्तिनः ॥
spies as hunters may let off cruel beasts from traps; spies as snake charmers may let off highly poisonous snakes; those who keep elephants may let off elephants (near the enemy's camp).
english translation
lubdhaka vyaJjanA vA vyAla mRgAn paJjarebhyaH pramuJceyuH, sarpa grAhA vA sarpAn ugra viSAn, hasti jIvino vA hastinaH ॥
hk transliteration by Sanscript