Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 8 · Marriage
विवाहः
जामित्रशुद्ध्यैकविंशन्महादोषविवर्जितम् ।एकविंशतिदोषाणां नामरूपफलानि च ॥ ४३४ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 434.
A lagna (rising sign) free of the 21 great faults, and free of jamitra (seventh-house fault). And the names, forms and results of the 21 faults
Simple meaning: Pick a lagna free of 21 great faults and with a pure 7th house.
वक्ष्यंतेऽत्र समासेन शृणु नारद सांप्रतम् ।
Now the 21 faults are told. The first is an impure almanac.
उदयास्तशुद्धिर्हानिर्द्वितीयः सूर्यसंक्रमः ।
More faults: rising and setting, the Sun's sign change, bad divisions, Venus in the 6th, Mars in the 8th.
गंडांतं कर्तरी रिष्फषडष्टेन्दुगतो ग्रहः ।
More faults: gandanta, kartari, the Moon in the 6th, 8th or 12th, the 8th sign, and poison time.