Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · Signs, Planets, Birth
जातकम् १
मध्याद्भ्रष्टेर्के विदेशस्थे जननेनारिजन्म वै ।मंदेंगस्थे कुजेस्ते च ज्ञोस्फुजि मध्यगे विधौ ॥ ६९ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 55, verse 69.
When the Sun has fallen from the 10th, the father is abroad at the birth. Or Saturn is in the lagna (rising sign), or Mars in the 7th. Or the Moon stands between Mercury and Venus. (Our text is unclear here: a word in the first line is damaged.)
Simple meaning: The Sun past the 10th, Saturn in the lagna, or Mars in the 7th can mean the father is away.
चतुष्पदर्क्षगे भानौ शेषैर्बलयुतैः खगैः ।
The Sun in a four-footed sign with strong planets can give twins in one sac.
सार्क्यारसिंहोज्ञाजांसे भांशतुत्यांगनालयुक् ।
A lagna in Leo, Taurus or Aries navamsha with Saturn or Mars can mean the cord wraps a limb.
सपापगोऽर्को जायो वा परवीर्यप्रसूतिकृत् ।
With these placements, the verse says the child may be from another man.