'Raksha Bandhan' celebrates the bond of affection between brothers and sisters, the day when siblings pray, well being and wish for each others' happiness and goodwill.
The name 'Raksha Bandhan' suggests 'a bond of protection'. On this auspicious day, brothers make a promise to their sisters to protect them from all harms and troubles and the sisters pray to God to protect their brother from the evils. The festival falls on the 'Shravan Purnima' which comes generally in the month of August. Sisters tie the silk thread called 'Rakhi' on their brother's wrist and pray for their well being and the brothers promise to take care of their sisters.
As 'The Lord Krishna' when killed the 'Shishupal', He was hurt and started bleeding from His finger. Bearing in mind 'Draupathi' had torn a strip of cloth from her sari and tied around his wrist to stop the bleeding. After realizing her affections and concern about him, declared himself bounded by her sisterly love. He promised her to repay this debt whenever she need in future.
Years later, when the 'Pandavas' lost 'Draupathi' in dice and 'Dhushasan' was removing her saari, that time 'Lord Krishna' helped her divinely elongating the 'saari' so that they could not remove it.
'Lord Krishna' protects his sister 'Draupathi' as brother, and repays this dept of her sister 'Draupathi'.
