Question: When we repeat mantras it is a common recommendation to repeat them 108 times and when we sing the bhajans here I notice that we sing the stanzas 3 times. Is there any significance in these numbers?
Numbers do have some significance. For instance we give the instruction to "meditate for one hour." When you do this, you will find that for the first 45 minutes or so you may experience that the mind is still unsettled. Only at the end of that one hour does it settle. It is simply like cooking something - it just simply takes that length of time to cook. In the same way the instruction for repeating the mantras, say 108 times, is given - it takes that long for the repetition to have its effect and for the mind to settle. But people misunderstand. They think that if they repeat the mantra 108 times they will get something like a certificate from God.
There are no hard and fast rules with these things. It is to achieve good results that that length of time or number of repetitions is recommended. God won't put you in prison if you do the recitation of the mantra less than 108 times.