probably) occurring in the present or future. In the former case, אִם is followed by the perfect, in the latter (corresponding to the Greek ἐὰν with the present subjunctive) by the imperfect or its equivalent (frequently in the apodosis also). On the other hand, לוּ (לוּלֵא) is used when the condition is to be represented as not fulfilled in the past, or as not capable of fulfilment in the present or future, and the consequence accordingly as not having occurred or never occurring. In the former case, לוּ and לוּלֵא are necessarily followed by the perfect (mostly also in the apodosis) corresponding to the Greek εἰ with the indicative of an historic tense, and the Latin imperfect or pluperfect subjunctive. In the latter case (which is extremely rare) the perfect, or the participle, or even the imperfect, may be used.
[m] Rem. Since it again frequently depends on the subjective judgement of the speaker (see under a), whether a condition is to be regarded as possible or impossible, we cannot wonder that the distinction between אִם and לוּ is not always consistently observed. Although naturally לוּ and לוּלֵא cannot take the place of אִם and אִם לֹא (on the strange use of לוּ in Gn 5015 see below), yet conversely אִם is sometimes used where לוּ would certainly be expected; cf. e.g. ψ 5012, 1375, 1398, Ho 912 (cf. verse 11). These examples, indeed (אִם with the imperfect), may without difficulty be explained from the fact that the connexion of לוּ with the imperfect was evidently avoided, because the imperfect by its nature indicates a still unfinished action, and consequently (as opposed to לוּ) a still open possibility. But אִם is also used for לוּ in connexion with the perfect, especially when an imprecation is attached by the apodosis to the condition introduced by אִם, e.g. ψ 74 ff. אִם־עָשִׂ֫יתִי זֹאת... יִֽרַדֹּף וג׳ if I have done this..., let the enemy pursue my soul, &c., cf. Jb 319 ff. The speaker assumes for a moment as possible and even actual, that which he really rejects as inconceivable, in order to invoke the most severe punishment on himself, if it should prove to be the case.
On the frequent addition of an infinitive absolute to the verb in clauses with אם see § 113 o above.
Examples:—
[n] A. אִם 1. with perfect in the protasis to express conditions, &c., which have been completely fulfilled in the past or which will be completely fulfilled in the future (the perfect is here equivalent to the futurum exactum, § 106 o). The apodosis[1] takes—
(a) A perfect also, e.g. Pr 912 אִם־חָכַ֫מְתָּ חָכַ֫מְתָּ לָּ֑ךְ if thou art wise, thou art wise for thyself; ψ 7315 (see below on לוּ).
(b) Imperfect, e.g. Dt 3241 אִם־שַׁנּוֹתִי if I whet my glittering sword... אָשִׁיב I will render vengeance, &c.; Jb 915 f.30 (in both cases we should expect לוּ rather than אִם־; so also in ψ 4421 f., with an interrogative imperfect in the apodosis); Jb 1113 (the apodosis is in verse 15).
(c) Jussive (or optative), e.g. Jb 319 ff. (see m above); Gn 183.
