Arthashastra
अविश्वस्तो वा प्रत्येकशो यातुम् इच्छेद् राज्य एक देशं वा यातव्यस्य आदातु कामः, तथा अप्य् एनं वैरिणा सर्व संदोहेन वा घातयेत् ॥
If, trusting to none, he wants to march alone in order to capture a portion of the territory of an assailable enemy, then he may be slain by employing one of his enemies or any other person provided with all necessary help.
english translation
avizvasto vA pratyekazo yAtum icched rAjya eka dezaM vA yAtavyasya AdAtu kAmaH, tathA apy enaM vairiNA sarva saMdohena vA ghAtayet ॥
hk transliteration by Sanscript