Arthashastra
"प्रभूत गुण बद्ध अन्य कुप्य यन्त्र शस्त्र आवरण विष्टिर् अश्मि समग्रं मे सैन्यम्, ऋतुश् च पुरस्तात्, अपर्तुः परस्य, व्याधि दुर्भिक्ष निचय रक्षा क्षयः क्रीत बल निर्वेदो मित्र बल निर्वेदश् च" इति पर्युपासीत ॥
When the conqueror thinks: "My army is provided with abundance of staple corn, raw materials, machines, weapons, dress, labourers, ropes and the like, and has a favourable season to act, whereas my enemy has an unfavourable season and is suffering from disease, famine and loss of stores and defencive force, while his hired troops as well as the army of his friend are in a miserable condition,"--then he may begin the siege.
english translation
"prabhUta guNa baddha anya kupya yantra zastra AvaraNa viSTir azmi samagraM me sainyam, Rtuz ca purastAt, apartuH parasya, vyAdhi durbhikSa nicaya rakSA kSayaH krIta bala nirvedo mitra bala nirvedaz ca" iti paryupAsIta ॥
hk transliteration by Sanscript