Verse 6: That this may be a sign among you, that (Josh. 4:21; Ex. 12:26; 13:14; Deut. 6:20; Ps. 44:1; 78:3-6) when your children ask their fathers in time to come (Heb. to morrow), saying, What mean ye by these stones?
[That it may be a sign among you] Of the matter conducted in this place (Menochius), that is, which shall bring back into memory for you so great a blessing (Vatablus). A sign and trophy of Jordan conquered by you and bound, as it were, and thence of the entire land of Canaan (Lapide). The goodness of God toward mankind is to be admired here, who, being conscious of human carelessness and senselessness, orders such an event to be marked with twelve stones, that He might rescue it from oblivion. Thus He furnished other helps: the Rainbow, Genesis 9:13; Circumcision, Genesis 17:11; Passover, Exodus 12 (Masius).
A sign; a monument or memorial of this day’s work.
[And when (thus Masius, Septuagint), כִּי] Because they shall ask (Malvenda). Thus he shows the reason for placing the monument (Masius).
Verse 7: Then ye shall answer them, That (Josh. 3:13, 16) the waters of Jordan were cut off before the ark of the covenant of the LORD; when it passed over Jordan, the waters of Jordan were cut off: and these stones shall be for (Ex. 12:14; Num. 16:40) a memorial unto the children of Israel for ever.
Before the ark; as it were at the sight and approach of the ark, to give it and the Israelites a safe passage.
[When it crossed it, בְּעָבְרוֹ] When it (the Ark) crossed through Jordan (Montanus, Junius and Tremellius, etc.).
[Unto eternity, עַד־עוֹלָם] For a long time (Menochius, Bonfrerius, Drusius). No better or more useful inheritance from parents is able to be left to children than if they take care that they be established in true religion, etc. The piety of Joshua is to be observed here, who has a thankful heart, so fixed upon the blessings of God that, with words repeated again and again in commemoration of such an event, he is filled with the great pleasantness of recollection, and appears hardly able to satisfy himself (Masius).
Verse 8: And the children of Israel did so as Joshua commanded, and took up twelve stones out of the midst of Jordan, as the LORD spake unto Joshua, according to the number of the tribes of the children of Israel, and carried them over with them unto the place where they lodged, and laid them down there.
[Therefore, the children of Israel did] Thus those twelve men are called, because each was representing his Tribe (Masius).
 Hebrew: לְמַ֗עַן תִּֽהְיֶ֛ה זֹ֥את א֖וֹת בְּקִרְבְּכֶ֑ם כִּֽי־יִשְׁאָל֙וּן בְּנֵיכֶ֤ם מָחָר֙ לֵאמֹ֔ר מָ֛ה הָאֲבָנִ֥ים הָאֵ֖לֶּה לָכֶֽם׃
 Hebrew: מָחָר.
 Joshua 4:6: “That this may be a sign among you, that when your children ask their fathers in time to come, saying (כִּי־יִשְׁאָל֙וּן בְּנֵיכֶ֤ם מָחָר֙ לֵאמֹ֔ר), What mean ye by these stones?” כִּי can introduce a temporal, causal, or resultative clause.
 Genesis 30:33a: “So shall my righteousness answer for me in time to comeבְּי֣וֹם) מָחָ֔ר), when it shall come for my hire before thy face…”
 Exodus 13:14a: “And it shall be when thy son asketh thee in time to come (מָחָר), saying, What is this?”
 Proverbs 27:1: “Boast not thyself of to morrow (בְּי֣וֹם מָחָ֑ר); for thou knowest not what a day may bring forth.”
 Hebrew: וַאֲמַרְתֶּ֣ם לָהֶ֗ם אֲשֶׁ֙ר נִכְרְת֜וּ מֵימֵ֤י הַיַּרְדֵּן֙ מִפְּנֵי֙ אֲר֣וֹן בְּרִית־יְהוָ֔ה בְּעָבְרוֹ֙ בַּיַּרְדֵּ֔ן נִכְרְת֖וּ מֵ֣י הַיַּרְדֵּ֑ן וְ֠הָיוּ הָאֲבָנִ֙ים הָאֵ֧לֶּה לְזִכָּר֛וֹן לִבְנֵ֥י יִשְׂרָאֵ֖ל עַד־עוֹלָֽם׃
 Hebrew: וַיַּעֲשׂוּ־כֵ֣ן בְּנֵי־יִשְׂרָאֵ֘ל כַּאֲשֶׁ֣ר צִוָּ֣ה יְהוֹשֻׁעַ֒ וַיִּשְׂא֡וּ שְׁתֵּֽי־עֶשְׂרֵ֙ה אֲבָנִ֜ים מִתּ֣וֹךְ הַיַּרְדֵּ֗ן כַּאֲשֶׁ֙ר דִּבֶּ֤ר יְהוָה֙ אֶל־יְהוֹשֻׁ֔עַ לְמִסְפַּ֖ר שִׁבְטֵ֣י בְנֵֽי־יִשְׂרָאֵ֑ל וַיַּעֲבִר֤וּם עִמָּם֙ אֶל־הַמָּל֔וֹן וַיַּנִּח֖וּם שָֽׁם׃