'Children of Israel' in the Bible

Yet I hold it somewhat against you that you have among you some adherents of the teaching of Balaam, who taught Balak to entrap the children of Israel into eating meat that had been sacrificed to idols, and into immoral practices.

I heard that the number of those that were marked with the seal was 144,000. They were from every tribe of the children of Israel:

It had a great, high wall with twelve gates, and twelve angels at the gates, which had carved upon them the names of the twelve tribes of the children of Israel.