《资治通鉴·唐纪·唐纪三十》
这时吐蕃向西攻打勃律国，勃律派遣使者来求援，玄宗命令吐蕃罢兵，吐蕃不听，并打败了勃律，玄宗十分愤怒。
时吐蕃西击勃律，勃律来告急。上命吐蕃罢兵，吐蕃不奉诏，遂破勃律；上甚怒。
At that time, the Tibetans attacked the Puluo Kingdom in the west, and the Puluo sent envoys to ask for help. Xuanzong ordered the Tibetans to withdraw their troops, but Tibet did not comply, and defeated the Puluo instead, which made Xuanzong furious.