Luke 2:50
And they vunderstood not the saying which he spake unto them.
And they understood not the saying which he spake unto them.
NKJV: But they did not understand the statement which He spoke to them.
ESV: And they did not understand the saying that he spoke to them.
καὶ αὐτοὶ οὐ συνῆκαν τὸ ῥῆμα ὃ ἐλάλησεν αὐτοῖς.
v:
Luke 9:45 But they understood not this saying, and it was hid from them, that they perceived it not: and they feared to ask him of that saying.
Luke 18:34 And they understood none of these things: and this saying was hid from them, neither knew they the things which were spoken.