The brothers' plot reaches its climax through a calculated psychological maneuver. They present blood-stained evidence to their father, intending for him to draw a tragic conclusion on his own so they do not have to lie explicitly.
The primary approach among commentators is that the brothers sent the garment to Jacob through anonymous messengers [רשב״ם, שד״ל, פענח רזא, בכור שור, חזקוני]. This distanced them from the event, as they knew bringing it themselves might cause Jacob to suspect them of murder given their well-known jealousy and hatred [רמב״ן, בכור שור, חזקוני, ביאור יש״ר]. Furthermore, they lacked the courage to lie to their father face-to-face or witness his initial agonizing reaction [שד״ל]. Using messengers also explained the phrasing of their message; the messengers were instructed to refer to the garment as his son's tunic, whereas the brothers naturally would have called it Joseph's tunic [רבנו בחיי].
Conversely, a large number of commentators understand their action not as sending, but as destroying. They explain that the brothers used a sword to stab, cut, and tear the garment, simulating the bite marks and rips of a wild beast [רמב״ן, ספורנו, רד״ק, העמק דבר, הטור הארוך, רא״ש, רבנו בחיי]. Others suggest they dragged the tunic across the ground to give it a worn, battered appearance [הדר זקנים, דעת זקנים]. However, the idea of using a sword is rejected by some, who argue that a clean blade cut looks nothing like the ragged tear of a wild animal, concluding that the brothers must have simply sent the garment via another person [רלב״ג].
The overarching goal of this deception was to convince Jacob that Joseph was dead, ensuring he would not go searching for him and uncover the secret of the sale [בכור שור]. Beyond the physical cover-up, plunging Jacob into deep mourning served a spiritual purpose. The brothers knew that God's presence and prophetic vision do not rest upon someone in a state of sadness. By breaking their father's heart, they guaranteed he would not be able to discover the truth through prophecy [שפתי כהן].
They specifically chose to present the striped tunic, knowing its unique design would cause Jacob to identify it instantly [רמב״ן, העמק דבר, הטור הארוך]. Feigning ignorance, they ironically pretended not to recognize the very garment they despised so deeply [ברכת אשר על התורה]. By claiming they had simply found it and asking if it belonged to his son, they were effectively saying that while they saw it was a striped garment, only the person who sewed it could definitively confirm its owner [ביאור שטיינזלץ].
Their cruel request for Jacob to identify the garment carries a profound moral consequence. Commentators agree that Judah coined this specific phrasing to deceive his father. Consequently, God held him accountable measure for measure. Years later, Tamar would use the exact same words against Judah, asking him to identify her items, thereby forcing him to confront his own actions [קיצור בעל הטורים, רד״ק, דעת זקנים, ברכת אשר על התורה].