Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 5 · Portents, Comets
ग्रहचारः केतवश्च
घोरा गतिर्हरित्वाष्ट्रवसुवारुणभेषु च ।इंद्राग्निमित्रमार्तंडभेषु पापाह्वया गतिः ॥ ४७ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 47.
The path is fierce in Shravana, Chitra, Dhanishta and Shatabhisha. In Vishakha, Anuradha and Hasta the path is called bad.
Simple meaning: Mercury's path is fierce in some stars and bad in others.
प्राकृताद्यासु गतिषु ह्युदितोऽस्तमितोपिवा ।
In each path, Mercury stays hidden for as many days as it was seen.
चत्वारिंशत्क्रमात्रिंशद्रवींदू भूसुतो नव ।
Mercury stays seen a set number of days in each of its seven paths.
प्राकृतायां गतः सौम्यः क्षेमारोग्यसुभिक्षकृत् ।
Mercury's natural path brings welfare and health. The mixed and short paths are middling.