Until Shiloh comes – Vayyechi
The word Shiloh is difficult. Maybe it is geographical. Rashi says the reference to Shiloh alludes to the belief in the Mashi’ach, who will replace Judah as the leader in due course.
Rashbam thinks it alludes to King Solomon, whose royal sway was broad and enduring. (I Kings 5:4). Possibly Shiloh links to a root that means son or issue, and hence the verse means that Judah will rule as long as humanity lasts.
Ramban links the word with “kingship”, i.e. “as long as there exists rulership in Israel”.