The Quraan and hadeeth are replete with encouragement to make tasbeeh. The different du‘aas that are prescribed for different times of the day contain tasbeeh. When Nabi (sallallahu ‘alaihi wasallam) was approaching the end of his worldly life, Allah Ta‘ala instructed him in Surah Nasr to recite tasbeeh. The hadeeth also recommends the recitation of the surahs that start with tasbeeh when going to bed.
So what does tasbeeh mean and what does it entail? It means that we declare the purity of Allah Ta‘ala. However, what are we declaring that He is pure from? There are basically two things: (1) Dependence. Allah Ta‘ala is totally independent. On the other hand, the creation depends on others. We should have the feeling of dependence that we are always in need. The wealthy require the poor and the poor require the wealthy. At no point can one claim that he is totally independent. When one expresses his independence, then Allah Ta‘ala will show him how weak and dependant he is. (2) Declaring that Allah Ta‘ala is pure and free from the limits of time and place. This means that He has direct authority and immediate power. We may have authority and power, but it is limited and indirect.