I think one source that I saw said that David had 19+ wives. Solomon had 1,000, but he went outside Israel for some and these wives led him away from God, so most would use that to speak against poly.
I find this scripture interesting in the NLT because I it speaks of Christ...
Psalm 45:9 -
6 Your throne, O God, endures forever and ever.
Your royal power is expressed in justice.
7 You love what is right and hate what is wrong.
Therefore God, your God, has anointed you,
pouring out the oil of joy on you more than on anyone else.
8 Your robes are perfumed with myrrh, aloes, and cassia.
In palaces decorated with ivory,
you are entertained by the music of harps.
9
Kings' daughters are among your concubines.
At your right side stands the queen,
wearing jewelry of finest gold from Ophir!
Holy Bible, New Living Translation, (Wheaton, IL: Tyndale House Publishers, Inc.) 1996.
Be blessed,
Ray