Lord Krishna was once on the bed with acute pain in His head. Sage Narada asked Shri Krishna that he was much surprise by what has happened and the remedy for the same.
Shri Krishna replied that the remedy was simple and the headache would immediately abate if someone who loved him would give him water to drink, the water must have washed the lover's feet.
Sage went to Shri Krishna's wife Rukmani with the remedy. Rukmani denied giving the water that has washed her feet, for drinking purpose to Lord Krishna. The reason it would be a great sin giving water that has washed her feet, for drinking purpose to her husband and the Lord 'Shri Krishna'.
Narada then went with the same plea to Shri Krishna's sweet heart Shri Radha. Radha immediately washed her feet and gave the water to Narada. She said that she was aware ot the consequences of the same. She will have to go and suffer in the hell for this action, but she would not mind it. She was happy to suffer if that brought relief to her beloved 'Shri Krishna'.