Moses spoke to the heads of the tribes of the people of Israel, saying, “This is what the LORD has commanded.
1 And Moses spake. Moses teaches in this chapter that the vows which were made by persons who were not free, were not held good before God; and although no mention is made of male children, still, as their condition was the same, it seems that by synecdoche they must be included with the daughters and wives, unless perhaps God chose to pay regard to the weaker sex.
This law was delivered to the heads of the tribes that they might instruct those who were under their charge, explain the law to them, give then necessary cautions, and call them to account, if there were occasion, for the breach of their vows.
Commenting on Numbers 30:1-2
And Moses spake unto the heads of the tribes,.... Or the princes of them, who could more easily be convened, and who used to meet on certain occasions, and on whom it lay to see various laws put in execution: concerning the children of Israel; how they ought to conduct and behave in the following case, it being an affair which concerned them all: saying...