"you say" (Mk 15:2)

σὺ λέγεις.

"Keep awake"

Mk 13:33 NRSV:  "keep alert [(ἀγρυπνεῖτε, form of ἀγρυπνέω)]"
Mk 13:34 NRSV:  "be on the watch [(γρηγορῇ, form of γρηγορέω)]"
Mk 13:35 NRSV:  "keep awake [(γρηγορεῖτε, form of γρηγορέω)]"
Mk 13:37 NRSV:  "Keep awake [(γρηγορεῖτε, form of γρηγορέω)]"
Mk 14:34 NRSV:  "keep awake [(γρηγορεῖτε, form of γρηγορέω)]"
Mk 14:37 NRSV:  "keep awake [(γρηγορῆσαι, form of γρηγορέω)]"
Mk 14:38 NRSV:  "Keep awake [(γρηγορεῖτε, form of γρηγορέω)]"

Psalms of Solomon 17

Psalms of Solomon 17:23 (21) ff.,

• vv. 23 (21) ff. in The Apocrypha and Pseudepigrapha of the Old Testament in English, ed. R. H. Charles (Oxford:  The Clarendon Press, 1913), vol. 2, pp. 649 ff., trans. G. Buchanan Gray, and
• vv. 21 ff. (v. 21 being the versification in the Septuagint as edited by Ralphs) in The Old Testament Pseudepigrapha, ed. James H. Charlesworth (Garden City, NY:  Doubleday & Company, Inc., 1985), vol. 2, pp. 667 ff., trans. R. B. Wright.

"Peter. . . . 'rebukes' Jesus, as though he were trying to exorcise a demon"

Mk 8:32:  "Peter . . . began to rebuke [(form of ἐπιτιμάω)] him.  But . . . [Jesus] rebuked [(form of ἐπιτιμάω)] Peter, and said, 'Get behind me, Satan!"

Mk 1:25:  "But Jesus rebuked [(form of ἐπιτιμάω) the unclean spirit]. . . ."
Mk 9:25:  "he rebuked [(form of ἐπιτιμάω)] the unclean spirit. . . ."

Syrophoenician

"The term 'Syrophoenician' [(Συροφοινίκισσα, Syrophoinikissa)] indicates that this woman was from Phoenicia, located in the Roman province of Syria, or, more specifically, from the area of the old cities of Tyre and Sidon."

     The HarperCollins Bible dictionary, rev. ed. (San Francisco:  HarperSanFrancisco, HarperCollins, 1996), s.v. Syrophoenician, by Philip L. Shuler.

Mk 6:50 and Ex 3:14 compared

Mk 6:50:  ἐγώ εἰμι, "[It] is I", or, more literally, "I am"
Ex 3:14 LXX:  ᾿Εγώ εἰμι ὁ ὤν, "I am who I am". . . . ῾Ο ὢν, "I am"
Ex 3:14:  אֶֽהְיֶ֖ה אֲשֶׁ֣ר אֶֽהְיֶ֑ה, "I am who I am". . . . אֶֽהְיֶ֖ה, "I am"

Ex 3:14 LXX (NETS):  "And God said to Moyses, 'I am The One Who Is.'  And he said, 'Thus shall you say to the sons of Israel, "The One Who Is has sent me to you".'"

Intercalation

"a literary technique in which a narrative segment is interrupted by the embedding of a second narrative segment (a Zwischenepisode) within the first, after which the threads of the first are picked up again, producing an ABA' pattern of composition. . . .
     "Intercalations occur at least six times in Mark. . . ."

     David E. Aune, The Westminster dictionary of New Testament and early Christian literature and rhetoric (Louisville, KY:  Westminster John Knox Press, 2003), 230 (230-232), where there is, of course, much more, and a bibliography to boot.  REF BS2312 .A86 2003.