Gesenius' Hebrew Grammar/160. Concessive Clauses
160a Besides the use of the imperative in the sense of a concession, meant either seriously (§110a) or mockingly (§110f), and of concessive circumstantial clauses (§141e, §142d, and §156f), concessive clauses may be introduced—
160b (b) By גַּם כִּי yea though, Is 115 with imperfect; for which we find simply גַּם in Is 4915 with imperfect, yea, though these may forget, yet ...; on the other hand, with perfect, Jer 3625, ψ 959, Neh 61; finally כִּי גַם even if, though, Ec 414. 160c (c) By the preposition עַל־ governing a complete noun-clause, as Jb 1617 עַל לֹֽא־חָמָס בְּכַפָּ֑י notwithstanding that no violence is in mine hands, or a verbal-clause, Is 539. On עַל־ with the infinitive in a similar sense (equivalent to in addition to the fact that = notwithstanding that), cf. §119aa, note 2.