He has no Stone to see with, and cannot answer the summons.
When Hama had been summoned and had gone, Gandalf led Theoden to a stone seat, and then sat himself before the king upon the topmost stair.
Let them summon all who dwell nigh!
Forth Eorlingas!_ The guards, thinking that they were summoned, sprang up the stair.
Shadowfax tossed his head and cried aloud, as if a trumpet had summoned him to battle.
The King then chose men that were unhurt and had swift horses, and he sent them forth with tidings of the victory into every vale of the Mark; and they bore his summons also, bidding all men, young and old, to come in haste to Edoras.
None could pass the Teeth of Mordor and not feel their bite, unless they were summoned by Sauron, or knew the secret passwords that would open the Morannon, the black gate of his land.
These were Men of other race, out of the wide Eastlands, gathering to the summons of their Overlord; armies that had encamped before his Gate by night and now marched in to swell his mounting power.
Another dreadful day of fear and toil had come to Mordor; and the night-guards were summoned to their dungeons and deep halls, and the day-guards, evil-eyed and fell, were marching to their posts.
There are no more uses of "summon" in the book.
Show samples from other sources
I was summoned to the principal’s office.
I summoned all my courage and walked into the room.