三合敵得 If You Can Match Me
大聖道：「哥要說打，弟也不懼。但求寶貝，是我真心，萬乞借我使使。」牛王道：「你若三合敵得我，我著山妻借你；如敵不過，打死你，與我雪恨。」大圣道：「哥要说打，弟也不惧。但求宝贝，是我真心，万乞借我使使。」牛王道：「你若三合敌得我，我着山妻借你；如敌不过，打死你，与我雪恨。」
逐句解 Line by line
The Great Sage said, "If my elder brother will talk of fighting, his younger brother is not afraid."
要 is yào here, the modal — if you are going to talk about fighting. 不 takes bú before the falling tone of 懼.
"But it is in all sincerity that I ask for the treasure. I beg you ten thousand times to lend it me for a use."
使使 doubles the verb in the vernacular manner of 寬恕寬恕 and 周濟周濟 earlier in the chapter — but this doubling shrinks rather than intensifies, making the request sound like a small thing: just let me have a little use of it.
The Bull King said, "If in three bouts you can match me, I will have my mountain wife lend it to you; if you cannot match me, I shall beat you to death and wipe out my grudge."
著 is zhuó, the reading that means to send or make somebody do something — he will have his wife lend it, not lend it himself. 敵得 is the can-do shape and takes the toneless de.
The Bull King's terms convert the whole negotiation into a wager, and in doing so hand the Great Sage exactly what he came for. Until this moment the fan was in the keeping of a wife who had refused it; now the husband has undertaken, on a stated condition, to make her hand it over. The condition is three bouts, and three bouts against this opponent is not a serious obstacle.
The word carrying the promise is 著 in its causative sense — I will have my mountain wife lend it. It is the first time in two chapters that anybody has claimed authority over the Rākṣasī, and the claim is made by a man who has not been home in two years. Whether he still has that authority is the question the rest of the story will answer.