Suryasiddhanta 2.3

2.3

pravahākhyaḥ pravahasañjñako marudvāyuḥ paścimābhimukhamemastān grahān tukārāduccāni svoccābhimukhaṃ svasya pravahabhramaṇenoccaṃ bhāvapradhānanirdeśāduccatā yasyāṃ diśi tat svoccaṃ pūrvadik pūrvabhāga eva grahāṇāṃ pravahabhramaṇenagragamanadarśanāt tatsanmukhaṃ pūrvadiśīti tātparyārthaḥ | īrayet paścimābhimukhabhramaṇasiddhaprāggatagrahavilaṃbanarūpeṇa cālayatītyarthaḥ | ataḥ kāraṇāt te grahāḥ pūrvāparotkṛṣṭā uccadevataiḥ pūrvapaścimadiśorākṛṣṭāḥ pṛthagvidhāṃ prathamāvagataikarūpabhinnaprakārāvagatāṃ pratidinavilakṣaṇāṃ gatiṃ gamanakriyāṃ yānti prāpnuvanti | atravalaṃbana-
nākarṣaṇābhyāṃ pratidinaṃ grahāṇāṃ gateranyādṛśatvaṃ tadanusāreṇa grahacārajñānaṃ yuktamiti grahāṇāṃ spaṣṭakriyotpanneti bhāvaḥ | yadvā | nanu vāyurajjubhiḥ kathaṃ grahāṇāmākarṣaṇaṃ sambhavati tadrajjūnāṃ viralatayā ghanībhūtatvābhāvenākarṣaṇā yogyatvādityata āha | pravahaśceti | uccadevatāhastadvayasthitakakṣākārasūtraṃ vāyuḥ pravahavāyurbandhanāt pravahasañjño na paścimābhimukhabhramapravahātmakastān grahān svābhimukhaṃ svoccadevatāsthānasammukhamīrayet prerayati cālayati | tukārāduccasthānāt pūrvasthite grahe vāyuḥ paścimagatyā grahaṃ cālayati paścimasthe vāyuḥ pūrvagatyā grahaṃ cālayatītyarthaḥ | tathā ca kakṣākārasūtraṃ tadā tadā tathā tathā bhramatīti devatairākṛṣyata ityupacāro'cyata iti bhāvaḥ | ata eva grahāṇāṃ spaṣṭakriyotpannetyāha | pūrvāparāmakṛṣṭā iti | uccadaivataiḥ pūrvāparadiśayorakṛṣṭā grahāḥ pṛthagvidhāṃ madhyamātiriktaprakārāṃ gatiṃ gamanakriyāṃ yānti | ato na kevalaṃ madhyakriyayā nirvāhaḥ |
atha prāk paścādapakṛṣyanta ityuktaṃ viśadayati |