My feedback is more on the interpretation of that piece of scripture, which I think is more about Jesus answering the disciple’s question as to why He speaks in parables, then what it was Him inviting them to ask questions.
In fact, I think we see in Mark 4:13 that He is gently encouraging them to observe what is going on around them, taking stock of developments, think for themselves, and not ask so many questions,(at least in the context of that verse and surrounding verses), He is wanting them to develop discernment, I’ll elaborate a bit more below.
Mark 4:10-34 would be read in parallel with Matthew 13:10- 35 as they contain much of the same storyline and fill in some of the context and gaps that might be missing from each respective passage read in isolation.
We see in Matthew 13:10 that the disciples ask Christ why He speaks in parables.
His response in both Mathew 13:14-15 & Mark 4:12 is referencing Isaiah 6:9-10. So, we can assume that by His response in Matthew 13:14-15 & Mark 4:12, that when they asked Him about the parables in Mark 4:10, they were enquiring as to why He was speaking in parables, as is found in Matthew 13:10.
Isaiah 6:9-10 passage reads as follows:
Isa 6:9 He said, "Go and tell this people: “‘Be ever hearing, but never understanding; be ever seeing, but never perceiving.’
Isa 6:10 Make the heart of this people calloused; make their ears dull and close their eyes. Otherwise they might see with their eyes, hear with their ears, understand with their hearts, and turn and be healed.”
And later on in the chapter Isa 6:13 says:
Isa 6:13 But yet a tenth will be in it, And will return and be for consuming, As a terebinth tree or as an oak, Whose stump remains when it is cut down. So the holy seed shall be its stump."
The Isaiah passage in Matthew 13 & Mark 4 that Christ mentions was God placing an act of judgement on Israel, He had shut up their hearts and minds to Him so that they could not find Him, He is giving them a cosmic hiding as a nation, and as we see in Isaiah 6:13, God will keep a remnant, a tenth of Israel for Himself.
And those who are contrite in spirit and humble and truly seek Him will be this remnant, and they will ultimately be brought back into a sweet relationship with God, as seen in Isaiah 66.
The Isaiah 6 passage would have been a “Remez” (a part that explains the whole) that rabbis used in their teaching. Everyone knew the story so well, that using one small part would bring about the whole understanding and full story into play with just a few words. Thus, the disciples would have known, or start to realize, that Christ was referring to something being revealed to them that had been kept hidden from Israel up until that point, and only those who were part of the remnant would have the ability to understand.
Christ mentions the “mystery of the kingdom of God” 1 Corinthians 2:7 & Ephesians 3:4-6 would explain the mystery, that the Messiah would be a simple man and not this mighty figure who would have complete political and military might as the Jews were expecting, dying on a cross (this being a stumbling block to the Jews – 1 Corinthians 2) to reconcile man to Himself, and while He’s at it, joining Jew and Gentile together in His body (Galatians 2).
The disciples would come to know the full extent of the mystery at a later stage.
Keep in mind that at this stage of Christ’s ministry His mission was still only the Jews – Matthew 10:5-6 – Matthew 15:24.
Later on in Matthew 13: 34-35 he references a prophecy from Psalm 78:2 once again stating that He will intentionally speak to these people in dark (obscure/ not easily understood) sayings, and thus between the Isaiah 6 and Psalm 78 reference He is telling His disciples that the He is the fulfillment of that prophecy and that Israel is still under judgement.
Mark 4:24-25 then goes onto say:
Mar 4:24 Then He said to them, “Take heed what you hear. With the same measure you use, it will be measured to you; and to you who hear, more will be given.
Mar 4:25 For whoever has, to him more will be given; but whoever does not have, even what he has will be taken away from him.”
He is saying to His disciples, to those who truly seek Him, and truly desire to understand by being open to what He is saying, and applying their hearts and minds to His teachings, as they progress in discernment and intentionality of obtaining the truth through discernment, more discernment and knowledge will be given to them.
In Summary, I think the Mark 4:11 verse is more about a validation/affirmation of the disciples truly seeking to understand and forming part of those that are contrite in spirit etc. and thus they have the ability to understand and will continue to do so.
Why did I spend an hour to elaborate on this? Because I think it should be even more encouraging to us that when we truly seek God and the things of Him, He will give us an individual ability to grow in discernment and understanding of His word. Certainly, this can come about by asking questions, but I think that is secondary to diligently reading & mediating on His word & praying. He wants us to have a deep and personal relationship with Him and He extends that to us in this very special way.
Lastly, this is also a good apologetic when chatting with Jews, because they will come to realize that the gentiles understand their God they profess to worship and know so well, better than what they do, and speak about and confirm the prophecy that was given to Isaiah, confirming the act of judgement, the fact that Christ truly was the Messiah, and thus hopefully bring about repentance.
P.S. I love the idea of everyone asking questions and getting them answered, absolutely not opposing that, my discussion is more about the interpretation of the Mark 4 verse.