In other words, the side of Emperor Tenmu bribed Dogyo into stealing for the purpose of recovering the Kusanagi no tsurugi which YAMATO Takeru no Mikoto left in the care of Miyazu Hime at his own discretion, resulting in letting go of.
つまり、日本武尊が独断で宮簀媛に預け、結果的に手放すことになってしまった草薙剣を取り返すべく、道行を買収したわけである。