Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 10 · Yatra and Omens
यात्रा शकुनाश्च
रवींद्वयनयोर्यातमनुकूलं शुभप्रदम् ।तदभावे दिवारात्रौ यायाद्यातुर्वधोऽन्यथा ॥ ६३४ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 634.
A journey is good when the half-year course of the Sun and Moon both favour it. If not, go by day on the Sun's side or by night on the Moon's side. Otherwise there is a risk to the traveler's life.
Simple meaning: Travel when the Sun's and Moon's courses suit the direction. If not, use day or night, or life may be at risk.
मूढे शुक्रे कार्यहानिः प्रतिशुक्रे पराजयः ।
Venus set can bring loss of work. Venus in front of the traveler can bring defeat, and nothing cancels it.
वासिष्ठकाश्यपेयात्रिभारद्वाजाः सगौतमाः ।
These five clan lines have no fault of Venus in front.
एकग्रामे विवाहे च दुर्भिक्षे राजविग्रहे ।
This Venus fault does not count in these cases.