Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 8 · Marriage
विवाहः
त्यजेत्पंचैष्टिकं चापि विषसंयुक्तदुग्धवत् ।लग्नलग्नांशकौ स्वस्वपतिना वीक्षितौ युतौ ॥ ४४१ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 441.
Also drop the panchaishtika (five-fold fault), like milk mixed with poison. Take the lagna (rising sign) and its navamsha (one-ninth part of a sign). Their own lords should look at them or join them.
Simple meaning: Drop the five-fold fault. The lagna and its navamsha should be seen or joined by their own lords.
न चेद्वान्योन्यपतिना शुभमित्रेण वा तथा ।
If no lord or friendly planet sees the lagna and navamsha, the groom's life may be at risk.
एवं तौ न युतौ दृष्टौ मुत्युर्वध्वाः करग्रहे ।
If the 7ths get no help, the bride's life may be at risk at marriage. Avoid the Sun's crossing.
विवाहादिषु कार्येषु नाड्यः षोडशषोडश ।
Avoid 16 ghatikas on each side of the Sun's sign change. Use good six divisions for marriage.