Jamieson, Fausset and Brown on 2 Corinthians 4:18

18. look not at--as our aim.

things ... seen--"earthly things" (Php 3:19). We mind not the things seen, whether affliction or refreshment come, so as to be seduced by the latter, or deterred by the former [Chrysostom].

things ... not seen--not "the invisible things" of Ro 1:20, but the things which, though not seen now, shall be so hereafter.

temporal--rather, "for a time"; in contrast to eternal. English Version uses "temporal" for temporary. The Greek is rightly translated in the similar passage, "the pleasures of sin for a season."