Stones that were dislodged by the plow, or that were covered and became exposed — if there are two [stones] among them [that are] a two-man burden, they may be taken. Someone clearing stones from his field may remove the upper [ones] but must leave those which touch the ground. Similarly, [when clearing] a pile of pebbles or a heap of stones — he may remove the upper [ones] but must leave those which touch the ground. If there was bedrock or straw underneath them, they may be taken.