ייִדישער מחשבֿה אויף איוב 39:13

Be careful that the matter of your deeds to G-d won't be like that of a certain careless bird which the verse speaks of, which lays an egg on the ground and sits on it to warm it, whereby other living creatures damage the egg and no chick hatches from it, as the verse says: "For she leaves her eggs on the ground, and she warms herself on the earth. She forgets that a foot may crush them, and the beast of the field may trample them. [She is hardened against her young ones as though they were not hers; though her toil is in vain, she has no fear]" (Iyov 39:13-16), and the rest of the matter.

Be careful that the matter of your deeds to G-d won't be like that of a certain careless bird which the verse speaks of, which lays an egg on the ground and sits on it to warm it, whereby other living creatures damage the egg and no chick hatches from it, as the verse says: "For she leaves her eggs on the ground, and she warms herself on the earth. She forgets that a foot may crush them, and the beast of the field may trample them. [She is hardened against her young ones as though they were not hers; though her toil is in vain, she has no fear]" (Iyov 39:13-16), and the rest of the matter.