A clean conscience is the best pillow

दिवसेनैव तत् कुर्यात्
येन रात्रौ सुखं वसेत् ।
यावज्जीवञ्च तत् कुर्यात्
येन प्रेत्य सुखं वसेत् ॥

- विदुरनीतिः

Do such a work throughout the day, which lets you enjoy a sound sleep in the night. Do such a work throughout your life, which lets you enjoy the eternal peace after death.

A clean conscience is the best pillow.
Nothing can bring you happiness but yourself.