给我六个小时砍倒一棵树，我会用前四个小时磨斧头。

We searched Lincoln’s authoritative collected writings, speeches, letters, and recorded conversations, and found no trace of this line in any primary source from his lifetime. The earliest close matches found by Quote Investigator appear only in the mid-20th century, including a 1956 version credited not to Lincoln but to an unnamed woodcutter. Since the saying appears in print decades after Lincoln’s death and only later became attached to his name, the Lincoln attribution does not hold up. This is best treated as misattributed, with an anonymous/proverbial 20th-century origin.