Passage
This allegory spoke Jesus to them, but they did not know what it was [of] which he spoke to them.
This allegory spoke Jesus to them, but they did not know what it was [of] which he spoke to them.
John 10:4 When he has put forth all his own, he goes before them, and the sheep follow him, because they know his voice.
John 10:5 But they will not follow a stranger, but will flee from him, because they know not the voice of strangers.
John 10:6 This allegory spoke Jesus to them, but they did not know what it was [of] which he spoke to them.
John 10:7 Jesus therefore said again to them, Verily, verily, I say to you, I am the door of the sheep.
John 10:8 All whoever came before me are thieves and robbers; but the sheep did not hear them.
The verse centers on "allegory", "spoke", and "jesus". It is saying that the verse draws attention to "allegory" and "spoke", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 5's "But they will not follow a stranger..." into verse 7's "Jesus therefore said again to them Verily...", so "allegory" and "spoke" belong inside that flow. In John context, the local focus is the identity of Jesus, new birth, eternal life, and belief and unbelief.
A plain takeaway is to answer the verse's own emphasis on "allegory" and "spoke" with trust shaped by these words, not by a vague optimism outside the passage.