World's first pair of brother and sister

 Today is the Raksha Bandhan day.

Today a sister ties rakhi around her brother's wrist in a hope that he will protect her from all the difficulties.

This act was first seen during the Mahabharata time. 

It was the time when Krishna had differences with Shishupala. 

Krishna had promised to Shishupala 's mother that he will tolerate his 100 faults. But if he continues to do the same, he will not keep quite and will kill him. 

Shishupala, a bad man, has done 100 faults. Krishna as he promised didn't take any action. 

But when Shishupala as his 101 fault, kept on abusing Sri Krishna. 

That time as said, Krishna killed Shishupala using his Sudarshan Chakra. 

But at that time, even Krishna got injured and blood start to oozing out of his fingure. 

That time, his sister Draupadi  quickly tore her saree to get a piece of cloth so that she can tie it around the wounded finger. 

Krishna was happy with the timely  gesture of Draupadi and promised her that he would protect her from all the difficulties she would face later in her life. 

Same way, Krishna protected Draupadi from being half naked, when Dushasana was snatching her clothes over her. 

Krishna supplied unlimited amount of clothes when Dushasana was doing the shameful act thus protecting his sister 's pride in front of every one in the court of Dhritharashtra.