Rabbi Joseph Isaac Shneersohn, the sixth Lubavitcher Rebbe, writes in his memoirs:

One day in the summer of 1896 [when I was sixteen years old], my father [Rabbi Sholom DovBer Shneersohn, the fifth Lubavitcher Rebbe, the "Rebbe Reshab"] took me for a walk in the fields. The crops were ripening. A light breeze moved through the sheaves, ears of corn nodded and whispered to each other. My father said to me: "see my son - Divinity! Each movement of every ear of corn, and of every tuft of grass, was anticipated in the principal thought of the cosmic primordial man." (to simplify, maybe we should just say: is part of G‑d’s master plan).

We had gone into the forest, and I, absorbed in our conversation, stirred by the sound of my father’s voice and the purity of his words, had distractedly broken off a leaf from a tree and was holding it in my hand, tearing it to bits and dropping the pieces to the ground.

...every leaf of a tree is a creature that has in it divine life...

My father said: ‘The holy Ari used to say, apart from the fact that every leaf of a tree is a creature that has in it divine life, and was created by G‑d for some predesigned purpose, there is also contained in every leaf a spark of some soul that has descended to this world in order to be redeemed.

"And now, regard how careful a man must be in this world, whether awake or asleep. See, even now, as we were speaking about divine providence, you absentmindedly plucked a leaf , held it in your hand, tore it into little pieces, and scattered the pieces to the ground. Should one regard the G‑d’s creations so lightly? The Creator wrought this creation too for some purpose, there is divine life in it. Within its own body is contained its own life. In what way is the ‘I’ in the leaf less than your ‘I?’ Yes, there is a great difference. The leaf is in the category of the vegetative world, and you in the category of the ‘human.’ But everything created has its own end, and its divine obligation to accomplish something in the world."