New International Version
Jesus said, “Do not hold on to me, for I have not yet ascended to the Father. Go instead to my brothers and tell them, ‘I am ascending to my Father and your Father, to my God and your God.’”
‘I am ascending
Verb - Present Indicative Active - 1st Person Singular
The Greek present tense indicates continued action, something that happens continually or repeatedly, or something that is in the process of happening.
Jesus was telling Mary that he had an important appointment with the Father in real-time.
Jesus had risen, Matthew 12:
For as Jonah was three days and three nights in the belly of a huge fish, so the Son of Man will be three days and three nights in the heart of the earth.
Jesus had just ascended from the heart of the earth to the surface of the earth and was in the process of ascending higher. He didn't want Mary delaying this process of the first ascension after the crucifixion.
What does “ascend to the Father” mean here?
Ascend from the heart of the earth to the surface of the earth, then to the highest heaven to see the Father.
Why does Jesus ask Mary to share these specific words with His disciples?
To share the good news of his ascension.
Why would they be comforted to know that He ascends to the Father if they have not yet seen Him and do not even know that He is risen yet?
Mary had seen Him. Mary was the witness to them.
Why is that He tells Mary He has not ascended, but then immediately tells her to tell the disciples that He ascends?
He was in the process of ascension. It was not finished yet.