"Not one of them is broken" (34:20). John writes of the cross, "A bone of him will not be broken" (John 19:36). Is John quoting this psalm?

John doesn't say which Scripture he means. At the cross the soldiers "didn’t break his legs" (John 19:33), and John writes, "For these things happened that the Scripture might be fulfilled, ‘A bone of him will not be broken.’" (John 19:36). His words are close to the Passover rule, "Do not break any of its bones" (Exodus 12:46), "nor break a bone of it" (Numbers 9:12), and to this psalm: "He protects all of his bones. Not one of them is broken" (Psalm 34:20). In Hebrew all three have the same words for bone and break. Psalm 34 says this of "the righteous" (Psalm 34:19): in Hebrew the righteous is plural in 34:15 and singular in 34:19 and 34:21, and 34:19-20 go on with him and his bones. Exodus 12's line on the map and Numbers 9's notes set out how Christians read John's words; these notes don't repeat them or choose.