Tosefta zu Ijow 15:18

[Then] he (i.e. Rebbi Tarfon) said to them (i.e. his students), “I will ask [you another question].” They said to him, “Teach us our master.” He said to them, “Why did [the tribe of] Yehudah merit the kingship [of Israel]?” They said to him, “Because [Yehudah] admitted [that he impregnated] Tamar.” It happened [once] with four elders, that they were sitting in the gatehouse of Rebbi Yehoshua. [They were] Elazar Ben Matya, Chaninah Ben Chachinai, Shimon Ben Azzai, and Shimon Hateimani. And they were involved [in discussing] what Rebbi Tarfon taught to them, “Why did [the tribe of] Yehudah merit the kingship [of Israel]?” “Because [Yehudah] admitted [that he impregnated] Tamar.” They have added [another source to that explanation] on their own. “[It says in the book of Iyov], ‘… that which the wise related from their fathers and did not withhold. To them alone the earth was given…’ (Job 15:18-19)” He (i.e. Rebbi Tarfon) said to them (i.e. to the four elders), “Do they give reward for a transgression? But rather what is [the real] reason why did [the tribe of] Yehudah merit the kingship of Israel?” [The four elders said back to Rebbi Tarfon,] “Because he (i.e. Yehudah) saved his brother (i.e. Yosef) from death, as it is said, ‘Yehudah said to his brothers, “What benefit [will we have] if we kill our brother?”’ (Genesis 37:26) and it is written, ‘Let us go and sell him to the Ishmaelites…’ (Genesis 37:27)”8 He (i.e. Rebbi Tarfon) said [back] to them (i.e. the four elders), “It is enough that [the act of] saving [him] should [serve] as forgiveness for the [act of] selling [him to the Ishmaelites]. But rather what is [the real] reason why did [the tribe of] Yehudah merit the kingship of Israel?” [The four elders said back to Rebbi Tarfon,] “Because of [Yehudah’s] humility, as it is said, ‘And now your servant (i.e. Yehudah) will become a slave to my master (i.e. Yosef) instead of the boy (i.e. Binyamin).’ (Genesis 44:33) Also [the only reason that] Shaul merited the kingship [of Israel] was due to [his] humility, as it is said, ‘… may be my father will turn his attention away from the donkeys and will start to worry about us.’ (I Samuel 9:5) [Since Shaul said “us” and not “me”] he considered his servant as [important as] himself, but Shmuel did not do so, but rather [he said], ‘Your father stopped worrying about the donkeys and is worried about you, saying “What will happen to my son?”’ (I Samuel 10:2) And when he (i.e. Shaul) runs away from [accepting his newly appointed role of] leadership what does it say? ‘And they have asked God, “Is the man even here?” and God said, “Here he is hiding by the vessels.”’ (I Samuel 10:22)” He (i.e. Rebbi Tarfon) said [back] to them (i.e. the four elders), “Is not he (i.e. Yehudah) a cosigner? And in the end [it is the responsibility] of a cosigner to fulfill his pledge. But rather what is [the real] reason why did [the tribe of] Yehudah merit the kingship of Israel?” They said to him, “Teach us our master.” He said to them, “[The reason the tribe of Yehudah merited the kingship of Israel is] because they sanctified God’s name on the sea. When [all of] the tribes came and stood by the sea, this one said, ‘I will go down [into the water first]’ and this one said, ‘I will go down [into the water first].’ The tribe of Yehudah jumped up and went in first and sanctified God’s name [by doing so]. And regarding that moment it says [in Tehillim], ‘Save me God, because the water is up to my soul.’ (Psalms 69:2) And it also says, ‘When Yisrael was going out of Egypt, the children of Yakov from the nation of a foreign tongue, Yehudah was His sanctifier…’ (Psalms 114:1-2) Since Yehudah sanctified God’s name on the sea, therefore ‘…Yisrael his subjects.’ (ibid.) ”