Jatakaparijata 18.16

18.16

anyonyamiṣṭaprahayordaśāyāṃ bhuktau śubhaṃ ṣaḍbalaśālinoratu |
śatruprahau durbalaśālinau cet pākāpahāre tu tayoranarthaḥ ||

In the daśā and sub-period of two planets mutually favorable and endowed with the sixfold strength (ṣaḍbala), there is auspiciousness; / but if two inimical planets are devoid of strength, there is ruin in their period and sub-period.