4 and this has been brought to your attention, then you must investigate it thoroughly. If it is true and it has been proved that this detestable thing has been done in Israel,

Read Deuteronomy 17:4 Using Other Translations

And it be told thee, and thou hast heard of it, and enquired diligently, and, behold, it be true, and the thing certain, that such abomination is wrought in Israel:
and it is told you and you hear of it, then you shall inquire diligently, and if it is true and certain that such an abomination has been done in Israel,
When you hear about it, investigate the matter thoroughly. If it is true that this detestable thing has been done in Israel,