They put them
Until the next day,
Since it was already evening.”
καὶ ἐπέβαλον αὐτοῖς τὰς χεῖρας καὶ ἔθεντο εἰς τήρησιν εἰς τὴν αὔριον· ἦν γὰρ ἑσπέρα ἤδη.
The author of Acts indicated that these Jerusalem Jewish officials laid hands on or arrested Peter and John (καὶ ἐπέβαλον αὐτοῖς τὰς χεῖρας). They put them in custody (καὶ ἔθεντο εἰς τήρησιν) until the next day (εἰς τὴν αὔριον), since it was already evening (ἦν γὰρ ἑσπέρα ἤδη). Acts is the only Greek biblical writing that used this word ἑσπέρα, that means evening. These Jewish Jerusalem religious Temple leaders took the early followers of Jesus into custody. As it was already night time, they would have to wait until the next day before anything could be done with them. Have you ever been arrested?