《资治通鉴·唐纪·唐纪五十九》
这就像猛兽一样，在山林自我跳跃，时间长了，就会感到困乏，必然不敢随便离开自己的窝巢。
譬如猛兽，自于山林中咆哮跳踉，久当自困，必不敢辄离巢穴。
It is like a fierce beast leaping in the mountain forest, after a long time, it will feel exhausted, and will certainly be too afraid to leave its own den.