Edit: (Full text of the First Amendment that I could find) "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercis

Edit: (Full text of the First Amendment that I could find) "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances." It doesn't need to. Just as it doesn't need to have a provision for yelling "fire" in a crowded theatre. But such actions will have consequences. Congress has the authority "To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;". Assembling for the purpose of violence is by definition an insurrection. So if the First Amendment said nothing of peaceably assembling, we can assume it is meant so, otherwise the Constitution would say nothing of insurrections.