This is an unhappy expression, bringing in the name of God where it does not occur. In the O.T. it is chalilah, 'far be it.' Ge 44:7,17, etc. In the N.T. ?? ???????, 'let it not be.' Ro 3:4,6,31, etc.
it could not be so: but let God be true, and every man a liar; as indeed it has been written, In order that you may be justified in your words, and shall prevail, in your judgment.
It could not be so: then how will God judge the world?
Then do we make void the law through faith? It could not be so: but we establish the law.