Rashi on I Samuel
Through the second [of my two daughters] you will become my son-in-law. I have two daughters; through one of them, you will become my son-in-law.5See Maseches Sanhedrin 19b. And similarly did Targum Yonoson render, 'with one of the two.' Similarly [we find], "I hold three things [meaning, one of three things] over you,"6II Shmuel 24:12. as Scripture clarifies there, "choose one of them."7Ibid.