The Long Āgama Sūtra 27.9

27.9

太子白王言：「今夜十五日月滿時，與晝無異，宜集四兵，與共謀議伐於邊逆，然後還此共相娛樂。」

The prince said to the king, “Tonight is the fifteenth day full moon, and the day was no different. It would be fitting to assembly the fourfold army and make a plan of attack on our foreign adversaries. After we return, we’ll celebrate it together.”