ISB ~ Mark 11 v23

this mountain:Presumably a reference to Mt. Zion, where Jerusalem stands. Its dramatic removal illustrates the power unleashed through prayer (Mt 17:20; 1 Cor 13:2; CCC 2610).

• Jesus may allude to Zech 4:7, where the prophet describes a vision of Zerubbabel rebuilding the Temple after its first destruction (586 B.C.). In his way stood a great mountain that Zerubbabel had to clear away in order to begin construction.

Here too the mountain of Jerusalem and the Temple must be pushed aside to make room for a new Temple:the true house of prayer built of Christian believers quarried from all nations (Mt 16:18; 1 Pet 2:4-5). See note on Mt 24:1-25:46.