Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · Signs, Planets, Birth
जातकम् १
शेषा दिनादिकं योज्यं नैतत्पिंडनिसर्गयोः ।लग्नार्कचन्द्रमध्ये तु यो बली तद्दशा पुरा ॥ १३६ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 55, verse 136.
Add the days and the rest that remain. This is not done for pinda (total figure) and nisarga (natural lifespan). Among the lagna (rising sign), the Sun and the Moon, the strongest one's dasha (planet period) comes first.
Simple meaning: The strongest among the rising sign, Sun and Moon has its period first.
ततः केंद्रादिगानां तु द्वित्र्यादौ सबलस्य च ।
Planet periods run in order of house, strength and years.
षड्वर्गार्द्धस्य त्रिंशस्य त्रिकोणगश्च स्मरगः ।
Planets share the sub-periods by their house from the period lord.
क्रमः केंद्रादिकोऽत्रापि द्वित्र्यादौ सबलस्य च ।
The period lord's share is 84, a planet with it 42.