Kautilya's Arthashastra 7.3.26

7.3.26

mukhyastrībandhanaṃ kuryāt pūrvayoḥ paścime tv arim /
sādhayed gūḍham ity ete daṇḍopanatasaṃdhayaḥ //

In the first two forms of the peace, a woman of rank should be given as an hostage, and in the last, a secret attempt should be made to capture the enemy; these are the forms of peace concluded on the condition of supplying his army.