"Let Reuben live, and not die; and let not his men be few." (Deuteronomy 33: 6)
Moses gave one last blessing to the Twelve Tribes of Israel before He died.
He would not go with them over the River Jordan into the Promised Land because he struck the Rock instead of speaking to it, as the Lord had required him.
In Moses' final prayer, God's grace abounds toward Reuben, despite the previous rebuke of Jacob during his final days.
While Reuben had said "Thou shalt not excel", which includes the connotation of very few remaining after him, Moses declares "Let Reuben live."