《资治通鉴·唐纪·唐纪四十》
军吏也告诉各位将领，将士们有三百人请求衣内穿甲跟从郭子仪前去。
吏亦告诸将，将士请衷甲以从者三百人。
The military officer also informed the other generals, three hundred soldiers requested to wear armor under their clothes and follow Guo Ziyi to go.