The word(s) "wall" appears 20 time(s) in 20 verse(s) in Quran in Abdullah Yusuf Ali translation.

(11) Then Moses threw his rod, when, behold, it straightway swallows up all the falsehoods which they fake!

(12) Then We caused the earth to swallow up him and his house; and he had not (the least little) party to help him against Allah, nor could he defend himself.

(13) And those who had envied his position the day before began to say on the morrow: "Ah! it is indeed Allah Who enlarges the provision or restricts it, to any of His servants He pleases! had it not been that Allah was gracious to us, He could have caused the earth to swallow us up! Ah! those who reject Allah will assuredly never prosper."

(14) Each one of them We seized for his crime: of them, against some We sent a violent tornado (with showers of stones); some were caught by a (mighty) Blast; some We caused the earth to swallow up; and some We drowned (in the waters): It was not Allah Who injured (or oppressed) them:" They injured (and oppressed) their own souls.

(15) See they not what is before them and behind them, of the sky and the earth? If We wished, We could cause the earth to swallow them up, or cause a piece of the sky to fall upon them. Verily in this is a Sign for every devotee that turns to Allah (in repentance).

(16) Then the big Fish did swallow him, and he had done acts worthy of blame.

(17) Has the Story of the Disputants reached thee? Behold, they climbed over the wall of the private chamber;

(18) One Day will the Hypocrites- men and women - say to the Believers: "Wait for us! Let us borrow (a Light) from your Light!" It will be said: "Turn ye back to your rear! then seek a Light (where ye can)!" So a wall will be put up betwixt them, with a gate therein. Within it will be Mercy throughout, and without it, all alongside, will be (Wrath and) Punishment!

(19) They will not fight you (even) together, except in fortified townships, or from behind walls. Strong is their fighting (spirit) amongst themselves: thou wouldst think they were united, but their hearts are divided: that is because they are a people devoid of wisdom.

(20) Do ye feel secure that He Who is in heaven will not cause you to be swallowed up by the earth when it shakes (as in an earthquake)?