'Undertaking' in the Bible

‘What are you, O great mountain [of obstacles]? Before Zerubbabel [who will rebuild the temple] you will become a plain (insignificant)! And he will bring out the capstone [of the new temple] with loud shouts of “Grace, grace to it!”’”

So in the present case, I say to you, stay away from these men and let them alone, for if this plan or action is of men [merely human in origin], it will fail and be destroyed;