Pay close attention to the part that reads “... he did not follow the Lord completely, as David his father had done.” Now research and found out how many wives and concubines King David had. Find out how many he had before he was King. Find out what the prophet Nathan said about the number of David’s wives.
Deut 17:17 ....OR HIS HEART WILL BE LED ASTRAY
Note that the reason for not taking MANY wives is given. It does not prevent the taking of a couple or even several wives. BTW, the proper translation is not many, it is multiply. In verse 16 it talks about not multiplying horses to himself. Does that mean he can only have one horse?
The reason for not multiplying wives is not a prohibition on polygamy. The reason is to prevent from being led astray. And that is what the Bible’s rebuke of Solomon is about - not polygamy.
Also note that under the Law, in specific situations, polygamy was not only allowed but was REQUIRED. To assert otherwise is ignoring the Law, and exporting an agenda, not truth.
ONAN?
The NIV translates it as "take many";
the ESV as "acquire";
this online Hebrew Interlinear translates the Hebrew word ("irbe" -- other interlinears say "yarbeh") as "increase": See Online Interlinear
And yes, rabah can also = multiply.
Horses can multiply into generations of horses; wives don't multiply into generations of wives for the same husband (that's called incest).
The reason for not multiplying wives is not a prohibition on polygamy. The reason is to prevent from being led astray.
Think of this word picture -- a fence with a gate.
If, let's say, you had such a fence around your yard as a boy -- and a wild forest on the other side -- sure...the ultimate reason that your father might tell you NOT to go thru that gate is because of where you can wind up -- lost!
Even if we were to agree that the prohibition in such a situation is not that your father had a "thing" about going thru gates; the thing is that that particular gate was a given pathway to "astrayness" -- "lostness" -- then, yes, the given gate does become key.
Elsewise, Deut. 17:17 loses all meaning...Deut 17:17 zeroes in a just a few things that can lead your heart astray: Hoarding wives and hoarding wealth.
It does not prevent the taking of a couple or even several wives. BTW, the proper translation is not many, it is multiply...
The bottom line of Deut. 17:17a is not to take MANY wives. Now I've got "news" for you...by definition, poly = MANY!