Narapatijayacarya 4.4.17

4.4.17

samā tṛtīyage jñeyā mandā bhānau caturthage ||
vakrā syātpañcaṣaṣṭherke tvativakrāṣṭasaptame ||

when it is in the third, [their motion] is to be known as mean; when the Sun is in the fourth, slow; / when the Sun is in the fifth or sixth, it will be retrograde, but in the eighth and seventh, highly retrograde;