Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 6 · Calendar, Muhurta Elements
कालमानं मुहूर्ताङ्गानि च
सर्वत्र प्रथमं लग्नं कर्तुश्चंद्रबलं ततः ।कल्प्यामदिंदौ बलिनि सप्तमे बलिनो ग्रहाः ॥ ३०६ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 306.
In every work, first look at the lagna (rising sign). Then look at the doer's Moon strength. Weigh this. When the Moon is strong, the planets in the 7th are strong. (Our text is unclear here: why the 7th is named.)
Simple meaning: First check the rising sign, then the doer's Moon. A strong Moon makes the planets strong.
चंद्रस्य वलिमाधारमाधेय चान्यखेटकम् ।
The Moon's strength holds up the other planets.
चेदिंदुः शुभदः सर्वे ग्रहाः शुभफलप्रदाः ।
If the Moon is good, all planets give good. If bad, they give bad.
लग्नस्याभ्युदिता येंशास्तेष्वंशेषु स्थितो ग्रहः ।
A planet in the risen part of the rising sign acts as a 1st house planet.