Salamun Alaikum,
With respect brother Mubashir, I feel the apparent contradiction has only been ‘apparently’ introduced because
you have cited verse 30:50 and taken an unwarranted restrictive interpretation in
red to offer it as a seeming contrast with verse 47:4
047.004 "Therefore, when ye meet the Unbelievers (in fight), smite at their necks; At length, when ye have thoroughly subdued them, bind a bond firmly (on them): thereafter (is the time for) either generosity or ransom: Until the war lays down its burdens. Thus (are ye commanded): but if it had been God's Will, He could certainly have exacted retribution from them (Himself); but (He lets you fight) in order to test you, some with others. But those who are slain in the Way of God,- He will never let their deeds be lost"Verse 30:50 has little to do with verse 47:4. The first verse is talking about the category of 'right hands possess' (30:50) and the issue of Prophetic spousal legality, and verse 47:4 is implying captives and the need for them to be set free.
I feel if one understands 'right hands possess' correctly, then there is no confusion. The comparison of 30:50 with 47:4 then becomes akin to comparing chalk and cheese.
Please also note that the almost exclusive term for 'captives' or 'prisoners' in the Quran is 'asir' (2:85, 8:67, 7:68) (plural: asra or verb - asara to take captive). This is not the term used in 30:50.
So the simple answer is that there is
no confusion, only one seemingly introduced by comparing two unrelated, thematically unconnected verses.
I hope that helps, God willing.
Joseph.