徑到壇門 To the Altar Gate
大仙拽開步進前,三藏等隨後,徑到了壇門外。擡頭觀看,那裡有一座高臺,約有三丈多高。臺左右插著二十八宿旗號。大仙拽开步进前,三藏等随后,径到了坛门外。擡头观看,那里有一座高台,约有三丈多高。台左右插着二十八宿旗号。
逐句解 Line by line
The immortal strode out ahead, with Sanzang and the rest behind, and came straight to the outside of the altar gate.
拽開步: 拽 = zhuài, “to stride, drag one's steps forward” (pypinyin mis-defaults zhuāi). 三藏: 藏 = zàng.
Raising their heads to look, they saw there a high platform, some three zhàng and more in height.
觀看: 觀 = guān. Locative 那裡有: 那 = nà, “there was.” 三丈: the measure 丈 (zhàng) left untranslated — roughly ten feet each.
To left and right of the platform were planted the banners of the twenty-eight lunar mansions.
Durative 插著: 著 = zhe. 二十八宿: 宿 = xiù, the twenty-eight 宿 (lunar lodges). 旗號 “standards, banners.”
The narrative pauses for a set-piece description of the Daoist rain-altar — a convention of the genre, cataloguing the ritual apparatus before the ceremony proper. The twenty-eight-mansion banners announce a full astral-magical rite, and the mounting inventory (censer, tablets, vats, stakes) builds an impression of formidable machinery, all of which Wukong is about to render irrelevant with a word to the gods above.