“Your father Abraham reioyced to see my day: and he saw it, & was glad.”
1611 King James Version (KJV)
8:56 He saw it - By faith in types, figures, and promises; as particularly in Melchisedec; in the appearance of Jehovah to him in the plains of Mamre, #Gen 18:1|; and in the promise that in his seed all the nations of the earth shall be blessed. Possibly he had likewise a peculiar revelation either of Christ's first or second coming.
Joh 8:56 Your father Abraham rejoiced to see my day, etc. Saw it in promise by prophetic vision; whether or not "Abraham was greater" (Joh 8:53), he rejoiced in the hope of the revelation of Christ.