The answer is: His father sent a servant back to Mesopotamia to choose a wife from his own family

Gen 24:2-4

The story of how Isaac found his wife, Rebecca, is steeped in profound cultural norms of the ancient Near East, highlighting how families took utmost care in marital selection. Uniquely, Isaac's father, Abraham, wanted to ensure that his son's partner would share their faith and values, prompting him to use a servant—a fidus Achates of sorts—to travel back to Mesopotamia, which geographically suggests a strong connection to their origins.

Interestingly, the servant's mission wasn't just a wishful journey; he invoked prayer as a guiding force for success. Upon his arrival, he set a specific test for finding the ideal bride, asking God to help him identify the woman who would willingly serve water—not only for him but also for his camels. This dependency on divine intervention echoes a theme found throughout scripture: reliance on God for guidance in decision-making, emphasizing the importance of faith in partnership, alongside personal agency.

What’s more, the story showcases active agency in both Isaac and Rebecca. Although initially portrayed as a figure waiting, once they meet, there’s an unmistakable sense of partnership as Rebecca willingly leaves her family behind. This notion of marrying not solely for love but also intertwined with familial devotion resonates in many cultures today, illustrating timeless ideals about unity, commitment, and how tradition plays a role in enduring relationships. Isaac and Rebecca symbolize the harmonious blend of practical considerations and profound love—themes that remain as relevant today as they were thousands of years ago.