南天門外 Straight To The South Heaven Gate
好大聖，執著這牌位、香爐，將身一縱，駕祥雲，直至南天門外。時有把天門的大力天王與護國天王見了行者，一個個都控背躬身，不敢攔阻，讓他進去。好大圣，执着这牌位、香炉，将身一纵，驾祥云，直至南天门外。时有把天门的大力天王与护国天王见了行者，一个个都控背躬身，不敢拦阻，让他进去。
逐句解 Line by line
The fine Great Sage held the tablets and the incense burner, gave his body a leap, rode an auspicious cloud, and went straight to the outside of the South Heaven Gate.
著 is zhe, holding them and going on holding them all the way up. The detail matters: he is carrying his exhibits in his arms across the sky, and the novel will not let you forget them — the tablets are named eight times in this chapter and the burner six. 南天門 is the southern gate of heaven, the door every ascent in this book goes through.
The Mighty Heavenly King and the Kingdom-Guarding Heavenly King, who held the gate at that time, saw Pilgrim and every one of them bowed with hands behind his back and did not dare bar the way, but let him through.
控背躬身 is to hold the arms back and bend at the waist, the posture of a man getting out of somebody's way respectfully. The gatekeepers of heaven treating him like this is a piece of history in one gesture: five hundred years ago they fought him and it did not go well.
The ascent takes two sentences and no obstacles. That is itself the joke — the last time Pilgrim came through this gate it took an army to stop him, and now the guards simply stand aside.
He arrives carrying two painted boards and a censer, which is not how anybody has ever entered heaven before. The novel keeps mentioning the load because the load is the case.