the first Amendment states:
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.
This only mentions congress explicitly. According to https://www.law.cornell.edu/wex/incorporation_doctrine
The First Amendment has been interpreted by the Court as applying to the entire federal government even though it is only expressly applicable to Congress.
I would like to find the first court case where the first amendment was applied like this to the entire federal government(judiciary or executive).
Can you help?