自當理會 Leave It All to Me
我見了王，倘或賜齋，便來喚你等同享。」行者道：「師父放心前去，老孫自當理會。」那沙僧把行李挑至館中。我见了王，倘或赐斋，便来唤你等同享。」行者道：「师父放心前去，老孙自当理会。」那沙僧把行李挑至馆中。
逐句解 Line by line
When I have seen the prince, if he should grant us a meal, I shall come and call you to share it."
賜齋 is to bestow a vegetarian meal — 齋 is the specific word for food fit for a monk, and it is what a pious ruler offers visiting clergy. Tripitaka has just told Bajie there might be lunch in it, which is the one argument guaranteed to secure his cooperation.
Pilgrim said, "Go on ahead with an easy mind, Master. Old Sun will see to things."
老孫, old Sun, is Wukong's habitual way of naming himself — the same self-important third person Bajie uses when he calls himself old Pig. 理會 means to deal with a matter, to handle it, and it is still ordinary modern Chinese. Coming from Wukong the reassurance is entirely sincere and historically unreliable.
Sha Monk carried the baggage on its pole into the guest house.
Sha Monk does what Sha Monk does. 挑 is to carry on a shoulder pole with a load at each end, and the luggage has been his job since he joined the party. He says nothing at all in this scene and simply moves the bags indoors.
The negotiation ends with each disciple getting the assurance he needs: Bajie is promised food, Pilgrim is given authority, and Sha Monk is given nothing and picks up the luggage.
Pilgrim's promise to see to things is a small comic landmine. Every reader knows what happens when Wukong is left unsupervised in a strange town, and the novel plants the line and then, unusually, does not detonate it. Nothing goes wrong here at all.