The Bhagavad Gita with Commentaries of Ramanuja, Madhva, Shankara and Others.
Bhagavad Gita 1.3
http://www.bhagavad-gita.us/articles/657/1/Bhagavad-Gita-13/Page1.html
By Bhagavan Sri Krishna
 

Text 3

pasyaitam pandu-putranam
acarya mahatim camum
vyudham drupada-putrena
tava sisyena dhimata

Translation

O my teacher, behold the great army of the sons of Pandu, so expertly arranged by your intelligent disciple the son of Drupada. 

Commentary by Srila Prabhupada 

Duryodhana, a great diplomat, wanted to point out the defects of Dronacarya, the great brahmana commander in chief. Dronacarya had some political quarrel with King Drupada, the father of Draupadi, who was Arjuna’s wife. As a result of this quarrel, Drupada performed a great sacrifice, by which he received the benediction of having a son who would be able to kill Dronacarya. Dronacarya knew this perfectly well, and yet as a liberal brahmana he did not hesitate to impart all his military secrets when the son of Drupada, Dhrishtadyumna, was entrusted to him for military education. Now, on the Battlefield of Kurukshetra, Dhrishtadyumna took the side of the Pandavas, and it was he who arranged for their military phalanx, after having learned the art from Dronacarya. Duryodhana pointed out this mistake of Dronacarya’s so that he might be alert and uncompromising in the fighting. By this he wanted to point out also that he should not be similarly lenient in battle against the Pandavas, who were also Dronacarya’s affectionate students. Arjuna, especially, was his most affectionate and brilliant student. Duryodhana also warned that such leniency in the fight would lead to defeat.

Commentary by Sri Vishwanatha Chakravarthi Thakur
(combined commentary for verses 2 and 3)

"O teacher, see this great army of the sons of Pandu, arranged for battle by your intelligent disciple, the son of Drupada."

Understanding that Dhritarashtra wanted war, Sanjaya then spoke, to make him aware of the obstacles to fulfilling that desire.

Duryodhana, seeing the arrangement of troops (vyudham) being prepared by the Pandavas, then speaks with inner fear in nine verses, starting from the third verse.

He criticizes Dronacarya. He tells him that he is very foolish because Dhrstadyumna, the son of Drupada, was arranging the troops of the enemy. That person was Drona's student, having been taught by him, even knowing that he was born to kill him. "Dhrstadyumna is very intelligent (dhimata) because he has gained the knowledge of how to kill you from you, his enemy. See what will result from this in the future!"