Isaiah 63:12 → Psalm 78:13

Both texts recall the same moment with the same verb. Psalm 78:13 says God בָּקַע (baqa', "split") the יָם (yam, "sea") and made the מַיִם (mayim, "waters") stand like a wall; Isaiah 63:12 names Him the One who בָּקַע the מַיִם before them. Neither is quoting the other — both draw on Exodus 14:21, where that verb and noun first meet — but they put the identical memory to opposite work. Psalm 78 recites the sea to convict: the splitting heads a catalogue of wonders Israel watched and then forgot, "In spite of all this, they kept on sinning; despite His wonderful works, they did not believe" (78:32). Isaiah 63 recites the same splitting to plead: "Where is He who brought them through the sea?" (63:11) becomes "If only You would rend the heavens and come down" (64:1). One text says, look what He did and you still would not trust Him. The other says, look what He did — therefore do it again. Scripture keeps both, and both are true at once in anyone who remembers God's past mercies: the memory indicts our forgetting and authorizes our asking in the same breath. The two uses meet at Jerusalem, where Luke calls Christ's death and resurrection an ἔξοδος (exodos, "exodus, departure," Luke 9:31). There the indictment Psalm 78 levels falls on Him, and the plea Isaiah makes is answered in Him — so that remembrance stops being a rebuke and becomes an invitation.