It is instructive to read the full record[1] of this tedious and difficult piece of diplomacy, for it serves as an interesting example of Oriental subtlety and circumlocution, contrasted with the straightforward dealing of a high-minded Englishman.
The Amir wrote a letter to the Governor-General couched in most satisfactory terms, which he forwarded to Peshawar by the hand of his confidential secretary, and which received, as it deserved, a very friendly reply.

This resulted in Dost Mahomed sending his son and heir-apparent, Sardar Ghulam Haidar Khan, to Peshawar, and deputing him to act as his Plenipotentiary in the negotiations.

Ghulam Haidar Khan reached Peshawar in March, 1855, where he was met by the Chief Commissioner, and on the 30th of that month the treaty was concluded.
'It guaranteed that we should respect the Amir's possessions in Afghanistan, and never interfere with them; while the Amir engaged similarly to respect British territory, and to be the friend of our friends and the enemy of our enemies.' The Governor-General had at first resolved to entrust to Edwardes the duty of meeting the expected Envoy from Kabul, and orders to that effect were issued.

But Edwardes, more anxious for the success of the negotiations than for his own honour and glory, wrote to Lord Dalhousie suggesting that the Government of India should be represented by the Chief Commissioner of the Punjab, and promising to afford Sir John Lawrence all the assistance in his power.

Edwardes believed that the importance of the treaty would be enhanced in the eyes of the Afghans by the presence of the higher official; and in this opinion the Governor-General concurred.