שִׁמְעוּ שָׁמַיִם וְהַאֲזִינִי אֶרֶץ כִּי יהוה דִּבֵּר בָּנִים גִּדַּלְתִּי וְרוֹמַמְתִּי וְהֵם פָּשְׁעוּ בִ
If you read just the opening verses of Isaiah your preference for a past tense makes sense. But I am working with a reading of the entire scroll of Isaiah that sees the pattern of divine good - rebellion - punishment, and each stage in it, as occurring at many times and not just at this one time. Two points are relevant. One, a translation of a given passage in any biblical book depends on one's understanding of that whole book and the place of that passage in it; it is not solely a matter of the forms and syntax of the passage itself. Two, the Hebrew text - verbs, nouns, etc. - can often support a range of meaning but a translator into English has to choose only one part of that range. Both "YHWH has spoken" and "speaks" and "I reared" and "I rear" are possible depending on one's focus on just these verses or on the larger scroll.