From Morgoth's Ring: The Later Quenta Silmarillion (II)
Why didn't Fingolfin wait for the enitre council to gather? Did he felt ashamed for doing this? Is this the reason why Fingolfin forgave his brother and made his promise to follow him, so there would never be dissention among them?But even as he spoke, suddenly Fëanor appeared, and he strode into the chamber tall and threatening. A fire of anger was in his eyes, and he was fully armed: his high helm upon his head, and at his side a mighty sword. 'So' it is, even as I guessed,' he said: 'my haf-brother would be before me with my father, in this as in all other matters. He would not wait for the council, where all words would be heard by all, and answered. He would speak against me in secret. This I will not brook!' he cried, turning upon Fingolfin. 'Get thee gone, and take thy due place!' Then as a flash of flame he drew his sword. 'Get thee gone and dare my wrath no longer!'