Jatakaparijata 1.3

1.3

nīcastho ripurāśisthaḥ kheṭo bhāvavināśakaḥ |
mūlasvatuṅgamitrastho bhāvavṛddhikaro bhavet ||

A planet situated in its debilitation or situated in an enemy's sign is a destroyer of the house;
situated in its moolatrikona, its own sign, its exaltation, or a friend's sign, it becomes the promoter of the house's increase.