Horace, strolling along the Via Sacra, shook hands with an acquaintance. Arreptâque monu, “Quid agis dulcissime rerum?”
AEneas, in the temple of Dido, sees his lost companions enter, and “avidi conjungere dextras ardebant” (AEn., i. 514.)
Nestor shook hands with Ulysses on his return to the Grecian camp with the stolen horses of Rhesus. And in the Old Testament, when Jehu asked Jehonadab if his “heart was right” with him, he said, “If it be, give me thine hand,” and Jehonadab gave him his hand.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894