The Hecatoncheires (100-handers) contains the Greek word for hand (cheir). Cheir is found in the word chiromancy or cheiromancy, which is also known as palm-reading or palmistry.
"It was you, goddess, who delivered him by calling to Olympus the hundred-handed monster whom gods call Briareus, but men Aegaeon, for he is stronger even than his father; when therefore he took his seat all-glorious beside the son of Saturn, the other gods were afraid, and did not bind him."
Iliad Book I
"Ouranos (Heaven) was the first to rule over the entire world. He married Ge (Earth) and sired first the Hekatonkheires, who were names Briareos, Gyes and Kottos. They were unsurpassed in both size and power, and each had a hundred hands and fifty heads. After these he sired the Kyklopes, by name Arges, Steropes, and Brontes, each of whom had one eye in his forehead. But Ouranos bound these and threw them into Tartaros, a place in Haides’ realm as dark as Erebos, and as far away from the earth as the earth is from the sky . . ."
Pseudo-Apollodorus, Bibliotheca 1. 1 - 7 (trans. Aldrich)
"Of various forms unnumber'd specters more,
Centaurs, and double shapes, besiege the door.
Before the passage, horrid Hydra stands,
And Briareus with all his hundred hands;
Gorgons, Geryon with his triple frame;
And vain Chimaera vomits empty flame."
Vergil Aeneid Book VI Dryden translation
"Three other sons were born of Gaia (Earth) and Ouranos (Sky), great and doughty beyond telling, Kottos and Briareos and Gyes, presumptuous children. From their shoulders sprang a hundred arms [i.e. Hekatonkheires, "hundred-arms"], not to be approached, and each had fifty heads upon his shoulders on their strong limbs, and irresistible was the stubborn strength that was in their great forms."
Hesiod, Theogony 147 ff (trans. Evelyn-White)