[If] one uproots sets from his own [field] and replanted [them] in [another section of] his own [field], they are exempt [from tithes].  [If] one buys [produce] which is attached to the ground, it is exempt [from tithes].  [If] one harvested [produce] to send to his friend, it is exempt [from tithes]. R' Elazar ben Azaryah says: If similar [produce] is being sold in the market, this [produce] is obligated [in tithes].