1)
Did Shmuel judge Yisrael all his days?
1.
Malbim: It was all his days from when he became a Shofet; Radak - i.e. 13 years. (Refer to 1:22:4:1)
2.
Radak citing a Midrash: A Levi, from when he is in the womb, he is written in the ledger above.
