Daya or Compassion is a fundamental teaching of the Sikh religion and teachings can be found on DAYA. The other four qualities in the arsenal are: Truth (Sat), Contentment (Santokh), Humility (Nimrata) and Love (Pyar). These five qualities are essential to a Sikh and it is their duty to meditate and recite the Gurbani so that these virtues become a part of their mind.
The importance of Daya can be seen from the following Shabads from Guru Granth Sahib:
This concept says to not ignore tragedies that take place in the world but to face them head-on and do whatever is possible within ones means. As a Sikh you must feel the pain and suffering of other people involved in any tragedy.
Daya (usually spelt daia in Punjabi), from Sanskrit "Day" meaning to sympathize with, to have pity on, stands for compassion, sympathy. It means ‘suffering in the suffering of all others’. It is deeper and more positive in sentiment than sympathy. Daya, cognitively, observes alien pain; affectively, it gets touched by it and moves with affectional responses for the sufferer; and cognitively it moves one to act mercifully, pityingly, with kindness and forgiveness. One imbued with daya “chooses to die himself rather than cause other people to die,” says Guru Nanak (GG, 356).