Dear Aijaz,
In my humble opinion, in 8:67, ‘yuthkhina’ would simply mean ‘having battled strenuously against /subdued’ (enemies) as in 47:4, ‘athkhantumuhum’ (having subdued them). ‘asra’ here is used as a plural ‘noun’ (singular ‘asir’ - captive, prisoner of war) as in 8:70 (al-‘asra’). Also see 2:85 (usara). Its verbal root being ‘Alif-Sin-Ra,’ - to make captive, prisoner, joint/ligament etc. [1], as a verb, it is used in its imperfect active form in 33:26 - ‘wata’siruna’ (and you took captive of).
With 17:1, ‘asra’ is used as a ‘verb’ in its perfect active form meaning - ‘to make anyone to travel by night, repair to an upland,’ It roots from the verbal root ‘Sa-Ra-Ya’ which means ‘to travel during the night, to depart/pass’ [2].
Also, while in 89:4 it is used in its imperfect active form - idha ‘yasri’ (as it passes/recedes), it is used in the imperative in 44:23 - fa ‘asri’ (set out/depart!). Also see 20:77.
Noun derivatives of the root verb include ‘sariyyan’ (stream, rivulet, fountain, chief of the nation) as in 19:24 and ‘sarat’ (summit, highest point) among others.
Therefore, ‘asra’ as a noun in 8:67 has a literal meaning of ‘captives/prisoners of war’ with a verbal root ‘Alif-Sin-Ra’ while ‘asra’ as a verb in 17:1 has a different meaning of ‘to repair somebody to some place’ with a different verbal root ‘Sa-Ra-Ya.’
8:67 simply reads:
“It is not for a prophet to take captives/ prisoners (of war) until he subdues - through strenuous battling (Allah's enemies) in the land (battlefield). Some Muslims desire the commodities of this world, but Allah desires [for you] the Hereafter. And Allah is Exalted in Might and Wise.”
Hopefully that somehow helps God willing.
Regards,
Athman.
REFERENCES:
[1]. Lane’s Lexicon Volume 1, Pp 94 & 95.
[2]. Ibid Volume 4, Pp 79 & 80.