You yourself should know how much you can give. You cannot give beyond your capacity. If you have done a lot of service that day, and if you are really tired, you should say no. Otherwise you are saying no to your own body or mind. In the name of helping others, you should not put your body into a situation where it might get hurt. Your conscience will tell you if you are finding an excuse; but if you really need the rest, then you can honestly say no. You don’t have to feel guilty about it.
Why should you feel guilty? Nobody expects you to go beyond your capacity. If you try to do something beyond your capacity, you might even make a mess of it. So, know your capacity, know your limitations. Then offer your services. There’s no need to feel guilty at all. If you feel guilty, then maybe you can do it but you just don’t want to. If your conscience is clear, you don’t have to feel guilty.
Ask advice from your own pure Self. Your conscience is always clean. That’s the part of God in you. It’s what you call the Guru within. It’s not necessary to always get advice from someone outside. The conscience is constantly giving us advice, but often we don’t listen to it. We don’t even want to listen. Someone else can only help you for a while.
You should learn to ask that buddy within. Sometimes you might feel a conflict: “I don’t know which is the self and which is the ego. One says, ‘Do it,’ the other says, ‘Don’t do it.” In that case go to someone who is capable of recognizing the difference. But, ultimately, we have to develop the capacity to discriminate within ourselves. That is why meditation is so important. Until you become established in that, at least in meditation you should be able to hear your own inner self.
By Swami Satchidananda, retrieved from his book The Golden Present