Brihat Samhita
एकऋक्षे चत्वारः सह पौरैर्यायिनो अथ वा पञ्च । संवर्तो नाम भवेत्शिखिराहुयुतः स सम्मोहः ॥ २०-०६ ॥
If in a single sign, Paura planets and Yāyin planets should meet together to the number of 4 or 5, the meeting is known as Saṃvana. If either Rāhu or Ketu should join them the meeting is known as Sammoha.
english translation
ekaRkSe catvAraH saha paurairyAyino atha vA paJca । saMvarto nAma bhavetzikhirAhuyutaH sa sammohaH ॥ 20-06 ॥
hk transliteration by Sanscript