which seems to be John's version of the stone rejected by the (house)builders (of Psalms 118:20) as the son of man rejected by the elders and the chief priests and the scribes (Mark 8:31 and 12:10)
Rashi: God made the stones that Jacob took of that place into one stone, "even achat" = Einstein!
κατὰ τὸ ῥῆμά σου
also in Luke 1:38
εἶπεν δὲ Μαριάμ, Ἰδοὺ ἡ δούλη κυρίου· γένοιτό μοι κατὰ τὸ ῥῆμά σου. καὶ ἀπῆλθεν ἀπ' αὐτῆς ὁ ἄγγελος. esv.org/Luke+1/
and I bet it builds on Deuteronomy 8 cited in Matthew 4:4,
ὁ δὲ ἀποκριθεὶς εἶπεν, Γέγραπται, Οὐκ ἐπ' ἄρτῳ μόνῳ ζήσεται ὁ ἄνθρωπος, ἀλλ' ἐπὶ παντὶ ῥήματι ἐκπορευομένῳ διὰ στόματος θεοῦ.
Verily I say unto you, This generation shall not pass, till all these things be fulfilled. Heaven and earth shall pass away, but my words shall not pass away.
John 1:15,
Ἰωάννης μαρτυρεῖ περὶ αὐτοῦ (= the word that became flesh)
καὶ κέκραγεν λέγων, Οὗτος ἦν ὃν εἶπον, Ὁ ὀπίσω μου ἐρχόμενος ἔμπροσθέν μου γέγονεν, ὅτι πρῶτός μου ἦν
Οὗτος ἦν also in John 1:2,
οὗτος ἦν ἐν ἀρχῇ πρὸς τὸν θεόν
cf. Rashi on Genesis 1:1
in the beginning it was his intention to create it with the standard of justice, but he perceived that the world would not endure; so he preceded it with the standard of mercy, allying it with the standard of justice