The author uses this rhetorical question to teach that when someone commands something to happen, it will happen only if God has already decreed that it should happen. AT: "No one has spoken and it came to pass, unless the Lord decreed it." or "What someone has commanded to happen has never happened unless the Lord decreed it." (See: [[rc://en/ta/man/translate/figs-rquestion]])
# has spoken
It can be expressed clearly that this refers to commanding something to happen. AT: "has commanded that something should happen" (See: [[rc://en/ta/man/translate/figs-explicit]])