There four things that are outwardly blessings but are inwardly obligatory:
1. Company of the righteous people is a blessing, but following them is an obligation.
2. Recitation of the Qur'an is a blessing, but acting on its instructions is an obligation.
3. Visiting the graveyard is a blessing, but earning its provisions is obligatory.
4. Caring for the sick is a blessing, but taking lessons from it (sickness) is obligatory.