Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · Signs, Planets, Birth
जातकम् १
अंशोनाः शत्रुभे कार्या ग्रहं वक्रगतिं विना ।मंदशुक्रौ विनार्द्धोना ग्रहस्यास्तंगतस्य च ॥ १२३ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 55, verse 123.
Cut a share of the years for a planet in an enemy sign, unless it is retrograde. Cut half for a planet set in the Sun's light, except Saturn and Venus. (Our text is unclear here: the size of the enemy-sign cut.)
Simple meaning: A planet's years are reduced when it is in an enemy sign or set in the Sun's light.
हानिद्वयेऽधिकाः कार्या यदा क्रूरस्तनौ तदा ।
When two cuts apply, only the bigger one is made. A cruel planet rising also cuts the years.
भगणांशैर्लब्धहीनास्तेषां कार्या विचक्षणैः ।
The rising planet cuts the years by a share. A bad one cuts the whole, a good one half.
स्पष्टास्तेंशाः खषट्त्र्यासा गुणयित्वा स्वकैर्गणैः ।
Degree parts are turned into years and months by multiplication and division.