In John 19:28, it is written,
28 After this, Jesus knowing that all things were now accomplished, that the scripture might be fulfilled, saith, I thirst. KJV, 1769
ΚΗʹ Μετὰ τοῦτο εἰδὼς ὁ Ἰησοῦς ὅτι πάντα ἤδη τετέλεσται ἵνα τελειωθῇ ἡ γραφή λέγει Διψῶ TR, 1550
In his commentary on John 19:28, Rudolf Ewald Stier remarks,1
Did the Lord Jesus Christ deliberately2 say “I thirst” in order to fulfill scripture, or did he say “I thirst” without pre-meditation and only happened to fulfill scripture as a consequence?
1 p. 3
2 i.e., designedly, intentionally, purposefully
Stier, Rudolf Ewald. The Words of the Lord Jesus. Trans. Pope, William B. Vol. 8. Philadelphia: Smith, 1860.