The opening wa connects the statement to its context. Lakum is a fronted prepositional phrase, fī l-qiṣāṣi another prepositional phrase, and ḥayātun a delayed indefinite subject. Detailed grammatical attachment may be analyzed in more than one way, while the central import remains clear.
Lakum highlights the beneficiaries, fī l-qiṣāṣi the institution through which the benefit arises, and ḥayātun the result. Word order and lexical choice are central to the verse's concision.