Midrash for Chullin 278:24

מכי יקרא נפקא כי יקרא פרט למזומן

For Rab Judah said in the name of Rab: If a man found a nest in the sea<span class="x" onmousemove="('comment',' A tree was washed away into the sea and upon it was a bird's nest.');">¹⁰</span>

Sifrei Devarim