50:36 And how many We destroyed before them of a generation, they (were) stronger than them (in) power. so they explored throughout the lands. Is (there) any place of escape?

18:97 So not they were able to scale it and not they were able in it (to do) any penetration.

5:12 And certainly took Allah a Covenant (from the) Children (of) Israel and We appointed among them two (and) ten (i.e twelve) leaders. And said Allah, "Indeed, I (am) with you, if you establish the prayer and give the zakah and you believe in My Messengers and you assist them and you loan (to) Allah a loan goodly, surely I will remove from you your evil deeds and I will surely admit you (to) gardens flow from underneath them the rivers. But whoever disbelieved after that among you, then certainly he strayed (from) the way, the right.