In hours of wealth, in time of woe, Him, sinless son, thy refuge know. From this good law the just ne’er swerve, That younger sons the eldest serve, And to this righteous rule incline All children of thine ancient line— Freely to give, reward each rite, Nor spare their bodies in the fight.

In plain words: Sumitra tells Lakshmana that Rama is his protector in good times and bad. She says the younger brothers of their family always serve the eldest, give generously, and fight bravely.