know this (ἰστε [iste]). Or “know this.” Probably the perfect active indicative (literary form as in Eph. 5:5; Heb. 12:17, unless both are imperative, while in James 4:4 we have οἰδατε [oidate], the usual vernacular Koiné perfect indicative). The imperative uses only ἰστε [iste] and only the context can decide which it is. Ἐστο [Esto] (let be) is imperative. Swift to hear (ταχυς εἰς το ἀκουσαι [tachus eis to akousai]). For this use of εἰς το [eis to] with the infinitive after an adjective