And Moses spake unto the heads of the tribes concerning the children of Israel, saying, This is the thing which the LORD hath commanded.

And he said to the princes of the tribes of the children of Israel: This is the word that the Lord hath commanded:

And Moses speaketh unto the heads of the tribes of the sons of Israel, saying, 'This is the thing which Jehovah hath commanded:

And Moses said to the heads of the tribes of the children of Israel, This is the order of the Lord.

And he said to the leaders of the tribes of the sons of Israel: "This is the word, which the Lord has instructed:

Et loquutus est Moses ad capita tribuum in Israel, dicendo: Hic est sermo quem praecepit Jehova.

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. But since He permits females, who were not under their father's power, to make vows in spite of their sex, nor does He make it to be an excuse for levity or thoughtlessness, it seems that the object proposed was, that the right of the father over his children as well as of the husband over the wife, should be maintained inviolate.

The regulations respecting vows appropriately follow those given respecting sacrifices, since a large proportion of vows would always relate to the presentation of such offerings. Rules had already been given Leviticus. 27 for the estimation of things vowed to God. It is probable that this fresh legislation dealing especially with vows made by persons in a state of tutelage, was occasioned by some case of practical difficulty that had recently arisen; and it is addressed by Moses to "the heads of the tribes" Numbers 30:1, who would in their judicial capacity have to determine questions on these subjects.
There is no provision in the chapter for annulling vows made by boys and young men; from which it has been inferred that the vows of males were in all cases and circumstances binding.

And Moses spake unto the heads of the tribes (a) concerning the children of Israel, saying, This [is] the thing which the LORD hath commanded.
(a) Because they might declare them to the Israelites.

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, this is the thing which the Lord hath commanded; relating to vows. Aben Ezra is of opinion that this was delivered after the battle with Midian, of which there is an account in the following chapter, and is occasioned by what was said, to the tribes of Gad and Reuben, Numbers 32:24.
do that which hath proceeded out of your mouth; to which they replied:
thy servants will do as my lord commandeth; upon which the nature of a vow, and the manner of keeping it, are observed; but the occasion of it rather seems to be what is said towards the close of the foregoing chapter, Numbers 29:39, that the various sacrifices there directed were to be offered in their season, besides the vows and freewill offerings; and when these were ratified and confirmed, and when null and void, and to be fulfilled or neglected, is the principal business of this chapter.

No man can be bound by his own promise to do what he is already, by the Divine precept, forbidden to do. In other matters the command is, that he shall not break his words, through he may change his mind.

VOWS ARE NOT TO BE BROKEN. (Numbers. 30:1-16)
This is the thing which the Lord hath commanded--The subject of this chapter relates to vowing, which seems to have been an ancient usage, allowed by the law to remain, and by which some people declared their intention of offering some gift on the altar or abstaining from particular articles of meat or drink, of observing a private fast, or doing something to the honor or in the service of God, over and above what was authoritatively required. In Numbers 29:39, mention was made of "vows and freewill offerings," and it is probable, from the explanatory nature of the rules laid down in this chapter, that these were given for the removal of doubts and difficulties which conscientious persons had felt about their obligation to perform their vows in certain circumstances that had arisen.

The rules by which vows were to be legally regulated, so far as their objects and their discharge were concerned, has been already laid down in Leviticus; but the chapter before us contains instructions with reference to the force of vows and renunciations. These are so far in place in connection with the general rules of sacrifice, that vows related for the most part to the presentation of sacrifices; and even vows of renunciation partook of the character of worship. The instructions in question were addressed (Numbers 30:1) to "the heads of the tribes," because they entered into the sphere of civil rights, namely, into that of family life.