Chapter 26
Plants and Trees
12.a. One is not allowed to lean against a tree, unless
1) one does so only lightly and
2) the tree is so firm that one cannot move it.
12.b. A person who is infirm should not lean against a tree even lightly, since, in spite of himself, he will lean against it with all his weight (and this would be considered as using the tree, which is forbidden by the prohibition set out in paragraph 14 below).
13.a. One must not climb a tree on Shabbath or Yom Tov, even if it is so firm that it does not move when one climbs it.
13.b. 1) If one has climbed it deliberately, knowing that it is forbidden, one may not come down until after Shabbath or Yom Tov.
2) However, if one did not know that what one was doing was forbidden, one is permitted, indeed one is obliged, to come down immediately.
