Matthew 24:45 and John 21:15-17 (Spiritual Feeding)

Τίς ἄρα ἐστὶν ὁ πιστὸς δοῦλος καὶ φρόνιμος ὃν κατέστησεν ὁ κύριος ἐπὶ τῆς οἰκετείας αὐτοῦ τοῦ δοῦναι αὐτοῖς τὴν τροφὴν ἐν καιρῷ (Matthew 24:45 NA28)

Ὅτε οὖν ἠρίστησαν λέγει τῷ Σίμωνι Πέτρῳ ὁ Ἰησοῦς· Σίμων Ἰωάννου, ἀγαπᾷς με πλέον τούτων; λέγει αὐτῷ· ναὶ κύριε, σὺ οἶδας ὅτι φιλῶ σε. λέγει αὐτῷ· βόσκε τὰ ἀρνία μου. λέγει αὐτῷ πάλιν δεύτερον· Σίμων Ἰωάννου, ἀγαπᾷς με; λέγει αὐτῷ· ναὶ κύριε, σὺ οἶδας ὅτι φιλῶ σε. λέγει αὐτῷ· ποίμαινε τὰ πρόβατά μου. λέγει αὐτῷ τὸ τρίτον· Σίμων Ἰωάννου, φιλεῖς με; ἐλυπήθη ὁ Πέτρος ὅτι εἶπεν αὐτῷ τὸ τρίτον· φιλεῖς με; καὶ λέγει αὐτῷ· κύριε, πάντα σὺ οἶδας, σὺ γινώσκεις ὅτι φιλῶ σε. λέγει αὐτῷ [ὁ Ἰησοῦς]· βόσκε τὰ πρόβατά μου (John 21:15-17 NA28). 

Maybe not significant, but different ways of describing spiritual nourishing/feeding occur in these accounts. Matthew writes: τοῦ δοῦναι αὐτοῖς τὴν τροφὴν ἐν καιρῷ ("to give to them their food [the food] in the appointed time/in season").

"Who then is the faithful and wise slave, whom the master has put in charge of his household, to give the other slaves their food at the proper time?" (NET Bible)

On the other hand, Jesus uses imperatival language in John, and admittedly, the setting is different: βόσκε τὰ ἀρνία μου ("feed my sheep"). But also, why that verb βόσκω? Evidently because it's related to feeding sheep and places the emphasis on the act of feeding.

Luke 12:42 has τοῦ διδόναι ἐν καιρῷ τὸ σιτομέτριον.

"The Lord said, 'Who then is the faithful and wise steward, whom his lord will set over his household, to give them their portion of food at the right times?'" (WEB)