Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 6 · Calendar, Muhurta Elements
कालमानं मुहूर्ताङ्गानि च
ग्रहयोगावलोकाभ्यां राशिर्धत्ते ग्रहोद्भवम् ।फलं ताभ्यां विहीनोऽसौ स्वभावमुपसर्पति ॥ ३०४ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 304.
A sign gives the result born of a planet through the planet's joining or looking. Without those two, it moves to its own nature.
Simple meaning: A sign gives a planet's result through joining or looking. Without them it acts by its own nature.
आदौ संपूर्णफलदं मध्ये मध्यफलप्रदम् ।
A rising sign gives full results at its start and small ones at its end.
सर्वत्र प्रथमं लग्नं कर्तुश्चंद्रबलं ततः ।
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.