Surya Siddhanta
उत्तराभिमुखम् पातो विक्षिपत्य् अपरार्धगः । ग्रहम् प्राग्भगणार्धस्थो याम्यायाम् अपकर्षति ॥
The Deity node draws the planet to the north or to the south (from the ecliptic) according as the node is west or east of the planet at a distance less than six signs.
english translation
uttarAbhimukham pAto vikSipaty aparArdhagaH । graham prAgbhagaNArdhastho yAmyAyAm apakarSati ॥
hk transliteration by Sanscript