Agni Purana (Jyotisha Selections) · by Vyasa
Chapter 3 · Name Letters and Chakras
युद्धजयार्णवः (चक्राणि)
विष्टिराहुं प्रवक्ष्यामि अष्टौ रेखास्तु पातयेत् ।शिवाद्यमं यमाद्वायुं वायोरिन्द्रं ततोऽम्बुपम् ॥ १४ ॥
In the full Agni Purana this is chapter 142, verse 14.
Now I will tell the Vishti Rahu. Draw eight lines. Go from Shiva's quarter to Yama's, then to Vayu's. From Vayu's go to Indra's, and then to the lord of the waters.
Simple meaning: Vishti Rahu uses eight lines moving round the directions from the north-east to the south, north-west, east and west.
नैर्ऋताच्च नयेच्चन्द्रं चन्द्रादग्निं ततो जले ।
Rahu with Vishti goes round the directions from the south-west through the north and south-east to the west and north-east.
ऐशान्यां च तृतीयादौ सप्तम्यादौ च याम्यके ।
Rahu sits in different directions on different moon days. In the north-west he kills enemies.
इन्द्रादीन्भैरवादींश्च ब्रह्माण्यादीन्ग्रहादिकान् ।
Groups of eight, led by Indra, Bhairava, Brahmani and the planets, go round from the east. Vatayogini starts from the south.