Matthew 12:24 does not support Robertson's argument for the so-called 'casual' use of eis. He knows that will not work here. Here, eis express point action. The men of Nineveh repented "at" the preaching of Jonah. If Matthew had meant to say that they repented "because of" the preaching of Jonah, he could have used 'dia' since it is with the accusative case and that would have conveyed the idea of 'because of'. Instead, Matthew uses a word that never means 'because of'. In
Matthew 26:28, Jesus says,
"This is My blood of the covenant, which is poured out for many for (eis) the forgiveness of sins." This is the exact same construction as that of
"be baptized for (eis) the remission of sins." Was Jesus blood shed because of the remission or to achieve the remission of sins?
There is nothing 'alleged' in what I am saying. What I am giving you are the simple grammatical facts.