Nothing save it were the power of God

First Nephi 18:8-23

Tying Nephi to the ship is the latest in a pattern of the murderous violence of Laman and Lemuel. They had been plotting to kill their father from the time they left Jerusalem, but as Nephi grew in status among the group, their anger grew toward him. Various events had softened Laman and Lemuel's hearts in the past. First, their father spake to them as he was filled with the spirit, which caused them to shake before him. An angel compelled them to stop beating Nephi and Sam. Ishmael's family persuaded them to stop trying to kill Nephi by tying him up and leaving him in the wilderness. The very voice of the Lord spoke to them "like unto the voice of thunder" and prevented them from killing their father and brother after Ishmael's death. Now Nephi was tied to the ship, a ship he built well enough to not only sail with the wind many days, but withstand four days of a great and terrible tempest. The pleading of his wife, children, and parents wouldn't soften Laman and Lemuel's hearts. As the verse above says, the only thing that could soften their hearts was their own imminent destruction by the power of God, another expression of their utter, consuming selfishness. This is the last significant effort to kill Nephi that ends in their repentance. The next one will end with Nephi leaving his brothers forever.