Why Did Jesus Teach in Parables?

The texts in full: Matthew 13:10–17, Mark 4:10–12, Luke 8:9–10 — "that seeing they may see, and not perceive" — quoting Isaiah 6:9–10, the prophet's hardening commission; beside them Mark 4:33–34, "with many such parables spake he the word unto them, as they were able to hear it," and Matthew 13:34–35 framing parable-speech itself as fulfillment of Psalm 78:2 (one of Matthew's ten formula quotations, per the atlas quotation-formulas lens). Two readings, both steelmanned: the judgment reading — after rejection, parables judicially veil the kingdom from the hardened while revealing it to disciples, in Isaiah's own pattern; the mercy reading — parables lodge truth past defenses exactly as Nathan's story caught David (2 Samuel 12), the veiling is invitational and temporary ("he that hath ears to hear, let him hear," Mark 4:9), and the common people "heard him gladly" (Mark 12:37). The tension is present in the same passages; the page adjudicates neither. Sources: KJV text (PD); parables brief §2.