There were such assertions by the apostles to Jesus. They might have been expressing their own belief and faith, but that does not mean their words were infallible when they said it. On the other hand you would be right that Jesus appears to endorse them because he doesn't deny them.
Besides, it could be true that Jesus knows all things, EXCEPT for certain things.
For example, Jesus said "a wicked generation seeks a sign but no sign will be given them"
And in another place Jesus said "a wicked generation seeks a sign but no sign will be given them EXCEPT the sign of Jonah the prophet."
Consequently, Jesus could know all things ... EXCEPT for the time when the world would end.
This approach to the NT is a bit dangerous. It opens the way to the attachment of the word EXCEPT to any sentence having the word ALL. For instance, in John's Gospel it is stated that ALL things were created by the Logos. Arians would easily read into this verse: "All things EXCEPT the Logos Himself were created by Him".
In Mark 8 Jesus does not refer to the sign of Jonah and naturally does not use a linguistic structure to indicate exception.
In Matthew we see Jesus refer to the sign of Jonah TWICE: chapter 12 and 16. The latter account corresponds to the instance in Mark 8, but its difference stems from Matthew's wish to accommodate it to his peculiar narrative in chapter 12. In other words, Matthew 16 talks about the sign of Jonah unlike Mark 8 because it is meant to be the parallel account of chapter 12, which was recorded by Matthew, but omitted by Mark. In Luke, on the other hand, Jesus talks about the sign of Jonah ONCE (chapter 11), which seems to be almost identical with Matthew 12.
Here He is using "know" in a poetic sense, as in to recognize. Their souls were isolated from Him, so He doesn't recognize them. If you take it to mean know, or literally have knowledge of their existence, while they exist and stand before Him, then it appears He doesn't literally know some things.
The verb used in both verses are identical in Greek. This is why some scholars think that Jesus knew that day and hour, but seemed ignorant of its knowledge.
Why is that saying he IGNORED the knowledge? He said he doesn't know.
When we use the term omniscient, don't we mean all-knowing, that he knows everything.
Or are you saying that Omniscient means that the person, on their own, CAN know everything, whether he ignores it or not, or actively thinks of it or not?
If Omniscient means that you have the POWER to know everything, then Christ appears omniscient, and you could say that he chose to ignore this ability in Mark 13:32.
But if Omniscient means literally that you do know everything, then Mark 13:32 seems to say Christ wasn't omnisicent.
Perhaps this is the best explanation, along with the possible explanation that Jesus allowed for EXCEPTIONS to things He said.
However you define "omnisicient" though, it still seems contradictory to say that He knows everything if He says He doesn't, unless you mean "know" in two different senses of the word.
Jesus knew everything, but He chose not to reveal SOME. The other possibility is that the knowledge of the day and hour was concealed from Jesus after the Incarnation. Since the Father did not allow mankind to know certain times defined by His authority, Jesus was not made exempt from this due to His human nature.
I mostly tend to take Jesus' words in Mark 13 metaphorically and think that He said the sentence not to give a lecture on theology or distinguish Himself from the Father, but to express with emphasis that it was not possible EVEN for Jesus' apostles to know the day and hour. The apostles seem to be people who believed in Jesus' full divinity and naturally expected Him to know and do EVERYTHING. Such an expectation is not wrong per se, but is not always in line with God's plans for mankind as it may go against the restrictions imposed by God on men. Jesus' statements in Mark 13 teach His disciples that they will not have any prerogatives with regard to knowledge of the day and hour although they are with the Son, who is equal to the Father.
I see a similar teaching in the following verses:
Then the mother of the sons of Zebedee came to him with her sons, and kneeling down she asked him for a favor. He said to her, “What do you want?” She replied, “Permit these two sons of mine to sit, one at your right hand and one at your left, in your kingdom.” Jesus answered, “You don’t know what you are asking! Are you able to drink the cup I am about to drink?” They said to him, “We are able.” He told them, “You will drink my cup, but to sit at my right and at my left is not mine to give
. Rather, it is for those for whom it has been prepared by my Father
.” (Matthew 20:20-23)
Should we conclude that Jesus was not omnipotent because He denied John and James the prerogative of sitting at HIS right and left hand? NO. Jesus could do that, but He did not want. He denied authority and responsibility for the things that would go against God's plans.
The other significant point is that in both instances the question/request concerns Jesus and are associated with His power. Jesus is the one to come on the Day of Judgment as the Lord of the house. Likewise, John and James request to sit at Jesus' right and left when He comes in HIS Kingdom. The denial of authority and responsibility in both cases may point at Jesus' humility, which resulted in His passion.