Dear Bhante,
I wish to delete my ‘wild’ interpretation. It is tooooooo wild!
Anyway, after searching for the Thai translation for this gatha, I’ve found that many scholars were struggling with the same phrase.
One website didn’t translate that phrase at all!!!
One translated it as:
ขอพวกศากยะและโกลิยะทั้งหลาย
จงได้เข้าเฝ้าพระองค์ที่แม่น้ำโรหิณีอันมีหน้าในภายหลังเถิด
= Let the Sākiyas and the Koḷiyas
have an audience with you at the Rohina River, which has face? later.
*Ajahn Chatchai can’t understand this translation.
Another:
ขอพวกศากยะและโกลิยะทั้งลาย
จงได้เข้าเฝ้าพระองค์ที่แม่น้ำโรหิณี อันมีปากน้ำอยู่ทางทิศใต้เถิด
= Let the Sākiyas and the Koḷiyas
have an audience with you at the Rohina River, the estuary of which is in the south.
*Ajahn Chatchai said that the word ‘Pacchāmukhaṃ’ here might be interpreted as modifying rohiniyaṃ. So, it can mean Rohina River, which faces the other way (here = south, as rivers flow southward).
Another:
พระประยูรญาติทั้งฝ่ายศากยวงศ์และโกลิยวงศ์จะได้เฝ้าพระองค์
ผู้ผินพระพักตร์ไปทางทิศตะวันออกซึ่งกำลังเสด็จข้ามแม่น้ำโรหิณี
= Your cousins and relatives in both the Sakiya and the Koliya clans can have an audience with you,
who faces east, while crossing the Rohini River.
*Ajahn Chatchai said that as the word Pacchāmukha means looking back, if the translator thought that it modified the Buddha, and the Buddha would be walking from the east to the west, the translator then could interpret that the text above meant the Buddha turn his face to look east. Ajahn disagreed with this interpretation, though.
*However, Aj Chatchai said that if the word Pacchāmukha here modifies the Buddha, it could mean the Buddha would be facing west, as Pacchā might mean west.
This translation project of yours is not only huge but also more than difficult!
With deepest respect for your determination and dedication!
Dheerayupa