The oxford definition of observe is to notice/perceive something and register it as being significant. Observe, observe, observe your body and mind. Let them speak to you. The quote to your left is one of my favorite quotes, and it is 100% true. If you don't observe your body and mind and refuse to listen to what is is trying to tell you it needs, you body/mind will make time to heal when it is the least convenient for you. 

We've been trained in this society that you have to push yourself all of the time, pain equals weakness, no pain no gain. All of these ideologies are simply not true. They are the opposite. They cause more harm than good. 

Our souls are housed in a human body which is a system. This system, like all systems, need times to rest and update. When your body/mind is ready for an update/rest, it will send you signals. You need to observe those signals and then implement what your body is asking for whether it be rest, water, or simply some food. 

Learn to observe your body/mind signals, learn how to decipher those signals, and then update/rest your system.