Abu Yazid made his periodic journey to purchase suplies at the bazaar in the city of Hamadhan --- a distance of several hundred miles. When he returned home he discovered a colony of ants in the cardamom seeds. He carefully packed the seeds up again and walked back across the desert to the merchant from whom he had bought them.
His intent was not to exchange the seeds but to return the ants to their home.
--- Sufi legend as recounted in
The Sun Magazine