Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 5 · Portents, Comets
ग्रहचारः केतवश्च
प्राकृताद्यासु गतिषु ह्युदितोऽस्तमितोपिवा ।यावंत्येव दिनान्येष दृश्यस्तावत्यदृश्यगः ॥ ४८ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 48.
In paths like the natural one, whether risen or set: for as many days as it is seen, it stays unseen for as many.
Simple meaning: 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.
वैशाखे श्रावणे पौषे आषाढेऽभ्युदितो बुधः ।
Mercury rising in some months brings bad results to the world. In other months it is good.