Deuteronomy 21:9

9 Forsooth thou shalt be alien, or unguilty, from the blood of the innocent which is shed, when thou hast done that that the Lord commanded. (And so thou shalt be free from any guilt for the innocent blood which is shed, when thou hast done what the Lord commanded.)

Deuteronomy 21:9 Meaning and Commentary

Deuteronomy 21:9

So shalt thou put away the guilt of innocent blood from among
you
Which otherwise, the person not being found out, and brought to just punishment for it, would devolve upon the whole. Aben Ezra interprets it the punishment of innocent blood, which, by the above method being taken, would not be inflicted on them:

when thou shalt do that which is right in the sight of the Lord;
as it was to observe this law concerning the beheading of the heifer, with all the rites and ceremonies belonging to it here enjoined; as well as every other command, statute, and ordinance of the Lord, which are all right to be done, ( Psalms 19:8 ) .

Deuteronomy 21:9 In-Context

7 and they shall say, Our hands shed not out this blood, neither our eyes have seen who shed it.

8 Lord, be merciful to thy people Israel, whom thou hast again-bought, and areckon thou not innocent blood in the midst of thy people Israel. And the guilt of blood shall be done away from them. (Lord, be merciful to thy people Israel, whom thou hast bought back, or hast redeemed, and put thou not the guilt of innocent blood on thy people Israel. And so the guilt for the innocent blood shall be done away from them.)

9 Forsooth thou shalt be alien, or unguilty, from the blood of the innocent which is shed, when thou hast done that that the Lord commanded. (And so thou shalt be free from any guilt for the innocent blood which is shed, when thou hast done what the Lord commanded.)

10 If thou goest out to battle against thine enemies, that thy Lord God betaketh them in thine hand, and thou leadest (back) prisoners, (When thou goest out to battle against thy enemies, and the Lord thy God delivereth them into thy hands, and thou takest some prisoners,)

11 and thou seest in the number of those prisoners a fair woman, and thou lovest her, and will have her to wife (and will have her for your wife),