Luke indicated that Jesus told them to make up or settle their minds or hearts (θέτε οὖν ἐν ταῖς καρδίαις ὑμῶν), so that they did not have to prepare their defense ahead of time (μὴ προμελετᾶν ἀπολογηθῆναι). This is unique use by Luke of the term προμελετᾶν, that means to premeditate, meditate beforehand, or prepare. Equivalent passages to this can be found in Matthew, chapter 10:19, and Mark, chapter 13:11. Mark indicated that Jesus told his disciples not to worry beforehand or be anxious about what to say (μὴ προμεριμνᾶτε τί λαλήσητε), when they were handed over and brought to trial (καὶ ὅταν ἄγωσιν ὑμᾶς παραδιδόντες). Matthew indicated that Jesus told his disciples not to worry or be anxious (μὴ μεριμνήσητε), when they were handed over (ὅταν δὲ παραδῶσιν ὑμᾶς) to these courts or tribunals. They should not worry about how or what they should say (πῶς ἢ τί λαλήσητε). It will be given to them (δοθήσεται γὰρ ὑμῖν) in that hour at that time (ἐν ἐκείνῃ τῇ ὥρᾳ) what they should say (τί λαλήσητε). Luke simply said that they were not to make any preparations for their defense. Would you like to be prepared before you went to court?
This is similar to Matthew, chapter 26:17, and Luke, chapter 22:7-8, but in Luke, Jesus was speaking to Peter and John explicitly. All three synoptic gospel writers said that this was the 1st day of the Unleavened Bread (Καὶ τῇ πρώτῃ ἡμέρᾳ τῶν ἀζύμων). Mark explained that the Passover lamb was sacrificed then (ὅτε τὸ πάσχα ἔθυον), but Matthew did not feel the need to explain that to his Jewish Christian readers. Some unnamed disciples spoke to Jesus (λέγουσιν αὐτῷ οἱ μαθηταὶ αὐτοῦ). They wanted to know where Jesus wished that they prepare to eat the Passover meal amonst themselves (Ποῦ θέλεις ἀπελθόντες ἑτοιμάσωμεν ἵνα φάγῃς τὸ πάσχα). At that time, it was the custom to go to Jerusalem to eat the Passover, not in their homes as later, after the destruction of the Temple. The question of whether this was the Passover or the day before the Passover seems somewhat moot, since this was the 1st day of the Unleavened Bread, when they ate the matzah bread, the Hebrew word for unleavened bread. The Passover meal itself usually included a lamb.