The pious servants of Allah Ta‘ala are not only kind to their friends, but rather they ensure that they do not bring any hurt to the heart of even their enemies unnecessarily. In fact, they aspire not to even bring hurt to an animal.
One buzurg purchased sugar and brought it home. On opening the parcel, he noticed an ant in it. He realised that this ant got into the sugar bag at the shop which he purchased it from. Hence, he took the pain of going all the way back to the shop in order to return the ant to its colony, solely with this concern that it may have felt hurt being away from its folks.
Although this is not something we need to emulate, the point to take note is what level of kindness flows from the hearts of these pious people.