This is an exerpt from 200 questions and answers in Aqeedah by Haafidh Ahmad Al-Hakamee you can find his biography at www.efatwa.com
Maa Ma3naa Ikhlaasun-Niyyah?
What is meant by a pure intention?
Huwa An Yakuna Maraadul Abd Bi-Jamee'3 Aqwaalihi wa A3maalihi Adh-Dhaahirat wa Baatinatu Ibtighaa Wajhillaahi Ta3alaa:
It is that the servant intends with all his statements and actions both outwardly and inwardly desiring only the face of his Lord the Most High:
Allaah the Might and Majestic says: "Wa Maa Umiroo Illa Liya3budullaaha Mukhliseena Lahu Deena Hunafaa'u" [98:5]
"And they were not commanded no more than to worship Allaah alone having sincerity for the upright religion."
Wa Qaala Ta3alaa: "Wa Maa Li-Ahadin I3ndahu Min Ni3matin Tujuzaa, Illab-tighaa'a Wajhi Rabbihil A3laa" [Layl 19-20]
"And who has [in mind] no favor from anyone to be paid back, except to seek the Face of His Lord the Most High." [Layl:19,20]
Wa Qaala Ta3alaa: " Innamaa Nuti'imukum Li-Wajhillah, Laa Nureedu Minkum Jazaa'an Wa Laa Shakoora" [Insaan:9]
"Indeed we only feed you desiring Allaah's Face, we are in no need of your rewards nor you thanks." [Insaan:9]
Wa Qaala Ta3alaa: "Man Kana Yureedu Hartha Al-Aaakheerati Nazid Lahu Fee Harthihi Wa Man Kana Yureedu Hartha Ad-Dunyaa Nu'teehi Minhaa Wa Maa Lahu Fil-Aaakheerati Min Naseeb" [Shurah :20] Wa Ghayrihaa Minal Aayaat."
"Whoever desires [by his deeds] the fruits of the life to come We shall increase it for him, and whoever desires [by his deeds] the fruits of this life then We shall give it to him from it [that which has been decreed for him] and in the life to come he shall have nothing." [Shura:20] And from other than this from the Ayaat of the Quran.
Sufyaan Ibn Uyainah used to say: Indeed the Deen is only in the Aathaar and not in opinions the Deen is in the Aathaar not in opinions...