君臣之禮 The Rites Of Prince And Minister
叫：「文武眾卿，寡人身虛力怯，不敢乘輦。汝等可替寡人，俱到朝外，敦請孫長老，看朕之病。汝等見他，切不可輕慢，稱他做『神僧孫長老』，皆以君臣之禮相見。」叫：「文武众卿，寡人身虚力怯，不敢乘辇。汝等可替寡人，俱到朝外，敦请孙长老，看朕之病。汝等见他，切不可轻慢，称他做『神僧孙长老』，皆以君臣之礼相见。」
逐句解 Line by line
He called out, "Civil and military officers all — I am weak in body and low in strength, and dare not ride in the carriage.
乘 is chéng, to ride — not the shèng of the Buddhist vehicle that 大乘 took earlier in the chapter.
"Go in my stead, all of you, out beyond the court, and respectfully invite the Elder Sun to look at my sickness."
敦請 is to invite with weight and ceremony. 替寡人 makes the errand an act of substitution rather than a delegation: they are to stand in his place.
"When you see him, on no account be casual with him. Address him as Divine Monk, the Elder Sun, and meet him with all the rites due between a prince and his ministers."
稱 is chēng, to style or address somebody as. 神僧 is the first of five uses of that title in the chapter, and 相 is xiāng in 相見, meeting one another.
The king cannot go, so he sends his court in his place and instructs it to behave as though the monk were the sovereign. 君臣之禮 is precise: the rites owed by a minister to a prince, to be performed by his ministers toward a stranger.
Eight Rules coached a street mob to say 孫老爺. The king, independently and some seven hundred characters later, has gone one better and settled on Divine Monk. The inflation is entirely self-generated — Pilgrim has claimed nothing but a hand that ends sickness.
And the man they are being sent to fetch is sitting in a hostel guest room with a stolen notice, having told his own master nothing at all.