The phrase ‘a simple jab of the knife’ means a swift blow of the knife.

The stem of a full-grown tree is very strong and the bark of it is very rough and hard. A knife is a weak object compared to the stem of a mature tree. If a knife is used to kill a tree, it can only leave some marks on the bark of it but cannot kill it. Therefore, ‘a simple jab of the knife’ will not be able to serve man’s purpose of killing a tree.

“It has grown/Slowly consuming the earth,”—Bring out the significance of this line.

The line mentioned above is taken from the poem ‘On Killing a Tree’ where the irony regarding the killing of a tree is expressed by the poet. The growth of a tree is like the growth of a child. It slowly consumes the earth, eats and drinks from it, rises out of the soil, feeds upon the earth’s crust and absorbs innumerable years of sunlight, air and water. As a human being, it takes several years to grow and mature. Therefore the line mentioned above marks the growth and development of a tree that takes a long span of time. Insensitive human beings cut trees deliberately without thinking of its consequences.