Titus Livius (Livy), The History of Rome, Book 29
Frank Gardener Moore, Professor Emeritus in Columbia University, Ed.

23. While these events were in progress among the Romans, the Carthaginians on their part, placing watch-towers on all the promontories, had passed an anxious winter, gathering information and alarmed by each fresh report. [2] And then, as no small factor in the defence of Africa, they added an alliance of their own with King Syphax, in reliance chiefly upon whom the Roman, they had believed, intended to cross over to Africa. [3] Hasdrubal the son of Gisgo had not merely a guest-friendship with the king, of which mention has been made above¹ —when Scipio and Hasdrubal coming from Spain arrived, as it happened, at the same time —but also the first proposal of a marriage tie was made, in which the king was to marry Hasdrubal's daughter. [4] To carry the matter through and to fix a time for the wedding, Hasdrubal went to him; for the maiden was already of marriageable age. On perceiving that he was [p. 299]fired with passion —and more than all barbarians² the Numidians are prone to sensuality —he summoned the maiden from Carthage and hastened the wedding. [5] And in the midst of congratulations on other grounds, in order that a public compact might be added to the private, an alliance between the Carthaginian people and the king was cemented by an oath, while a pledge was given by both sides that they would have the same friends and enemies.

[6] Hasdrubal, however, remembered not only the alliance with Scipio into which the king had entered, but also how naturally characterless and fickle are barbarians. He feared that if Scipio should cross over to Africa this marriage would be a slender bond. Consequently while the Numidian, fired by his newfound love, was in his power, with the help also of the young woman's allurements, Hasdrubal prevailed upon him to send ambassadors to Scipio in Sicily, and through these men he was to warn Scipio not to cross over to Africa in reliance upon his previous promises. [7] They were to say that he was [8??] linked with the Carthaginian people both by his marriage to a citizen of Carthage, daughter of the Hasdrubal whom Scipio had seen received as a guest in his own house, and by a public treaty as well; [9] that in the first place he wished that the Romans would carry on war with the Carthaginians, as they had done hitherto, far from Africa, making it unnecessary for him to be involved in their conflicts and to follow the arms of this side or that, rejecting alliance with the other side; [10] that if Scipio did not keep away from Africa and moved his army up to Carthage, it would be necessary for him to fight both for the land of Africa, in which he too had [p. 301]been born, and for the native city of his wife and for³ her father and her home.