Albert Barnes Commentary Deuteronomy 3:26

"But Jehovah was wroth with me for your sakes, and hearkened not unto me; and Jehovah said unto me, Let it suffice thee; speak no more unto me of this matter." — Deuteronomy 3:26 (ASV)

The Lord was angry with me for your sakes - Here, as in (Deuteronomy 1:37) and (Deuteronomy 4:21), the sin of the people is stated to be the ground on which Moses’ prayer was denied. In (Deuteronomy 32:51), and in (Numbers 27:14), the transgression of Moses and Aaron themselves is assigned as the cause of their punishment. The reason why one side of the transaction is put forward here, and the other elsewhere, is evident. Here Moses is addressing the people and mentions the punishment of their leaders as a most impressive warning to them, whose principal fault it was. In (Deuteronomy 32:0) and (Numbers 27:0), God is addressing Moses and, as is fitting, holds him accountable not for the sin of the people but for his own.