Rebels - S2E8 - "Blood Sisters"

3:34 - Sabine (to Ketsu):  "I saw your mark, old friend."  The phrase "old friend" is also used in Attack of the Clones (where Palpatine suggests "an old friend, like Master Kenobi" to protect Padmé [6:34] and Count Dooku calls Mace Windu "my old Jedi friend" [1:50:24] and just "old friend" [1:56:05]), in Revenge of the Sith (where Obi-Wan says, "Goodbye, old friend" to Anakin as he leaves for Utapau [51:13] and Yoda refers to Qui-Gon as "an old friend" [2:09:56]), in A New Hope (where Leia sarcastically says, "We, uh, ran into some old friends" when Han asks her and Luke where they've been [1:31:33]), in The Empire Strikes Back (where Yoda says that through the Force, Luke will see "Old friends long gone" [1:17:05]), and in Return of the Jedi (where Luke says, "I have a promise to keep to an old friend" [37:37] and Han calls C-3PO "an old friend of mine" [1:11:53]).

4:08 - Sabine (about breaking out of the Imperial academy):  "That was a long time ago."  Han uses the same expression in The Empire Strikes Back, after Chewbacca makes a comment that's evidently about something Han did to Lando in the past:  "Well, that was a long time ago; I'm sure he's forgotten about that" [1:18:44].  The phrase "A long time ago" is also shown at the beginning of each of the movies.

6:49 - Stormtrooper (as a fight breaks out with Ketsu):  "What the?"  In Attack of the Clones, an alien on Coruscant makes this same exclamation as he sees Obi-Wan flying through traffic while hanging from a droid [15:08]; Han Solo says it in A New Hope after emerging from hyperspace into a meteor shower [1:03:15]; and in Return of the Jedi, a scout trooper says this after being hit by Wicket [1:05:38].

7:20 - Stormtrooper (as Ketsu flies away):  "Bounty hunting scum."  Insults involving scum also appear in Revenge of the Sith (General Grievous calls Anakin "Jedi scum" [19:12]), The Empire Strikes Back (Admiral Piett remarks, "Bounty hunters!?  We don't need their scum." [1:05:52]), and Return of the Jedi (an Imperial officer says, "You rebel scum" [1:33:51]).

8:20 - Sabine (as Ketsu fires on the ship):  "Too late!"  In Return of the Jedi, an Imperial officer also shouts, "Too late!" [1:59:03] after Admiral Piett orders, "Intensify forward firepower!" to destroy an A-wing on a collision course with the Super Star Destroyer.

9:53 - Sabine (as Chopper lands on Ketsu's ship):  "I don't believe it."  Luke also says, "I don't, I don't believe it" in The Empire Strikes Back, after Yoda uses the Force to get his X-wing out of the swamp [1:13:10].

10:46 - Ketsu (as she's about to fire on Sabine):  "I really wish it hadn't come to this, old friend."  See above, 3:34.

11:01 - Sabine (to Ketsu):  "So long, old friend."  See above, 3:34.

13:00 - Ketsu (to Sabine, referring to Chopper):  "And this astromech, not very smart sticking your neck out for it."  C-3PO uses the same expression, also referring to an astromech, in A New Hope; he tells R2-D2, "Now don't you forget this.  Why I should stick my neck out for you is quite beyond my capacity." [19:30]

16:16 - Sabine (to the Imperial officer):  "It is looking pretty bad over here.  I'd keep my distance if I were you."  Han gives Chewbacca a similar suggestion in Return of the Jedi:  "Keep your distance, though, Chewie, but don't look like you're tryin' to keep your distance" [55:12].

17:50 - Ketsu (to Chopper):  "Get us out of here."  In A New Hope, Han also says this (to Chewbacca):  "Chewie, get us outta here!" [55:26].