Horus or Harpocrates was the son of Osiris. He is represented seated on a lotus flower, with his finger on his lips, as the god of Silence.
In one of Moore's "Irish Melodies" is an allusion to Harpocrates:
Thyself shall, under some rosy bower,
Sit mute, with thy finger on thy lip;
Like him, the boy, who born among
The flowers that on the Nile-stream blush,
Sits ever thus - his only song
To Earth and Heaven, "Hush all, hush!"
Bullfinches Mythology, Thomas Crowell & Co., New York, p. 293.
CIRCUMSTANCE: the Egyptian deity of silence