ahamdulillaah was. salaatu was. salaamu `alaa rasoolillaah. wa. ba`ad
These are some narrations brought by the Shaykh `Abdul-Malik ar-Ramadaanee (hafidhahullaah) in his excellent book "Sittu Durar":
It has been stated in definition of Ikhlaas, "Ikhlaas is when the servants internal and external actions are the same (i.e. are in agreement with each other). And Riyaa is when the external actions are better than the internal actions (of the heart). And truthfulness in one's sincerity is when the internal is better (developed) than the external. (Refer to Madaarij us-Saalikeen for this definition 2/91).
Bilaal bin Sa'd (rahimahullaah) said, "Do not be a wali (friend) of Allaah outwardly, yet an enemy to him internally" (Ahmad in az-Zuhd, Abu Nu'aym in al-Hilyah).
It has been stated, "Ikhlaas is that you do not request anyone to witness your action except Allaah, and that you do not seek anyone to reward you (for it) except Him".
Salamah bin Dinar said, "Hide your good deeds (from the people) just like you hide your evil deeds". (Abu Nu'aym, Bayhaqee) And in a narration in al-Bayhaqee, "Hide your good deed like you hide your evil deed, and do not be amazed with your own action, for you do not know whether you are happy or wretched (in the Hereafter)"
It has been stated in definition of Ikhlaas, "It is to single out Allaah, free from all imperfection, in one's intention (qasd) in one's obedience (to Him)."
Hammaad bin Zaid said, "I used to walk with Ayyoob (as-Sakhtiyanee) and he would take me through different routes. I would be surprised at how he would guide himself through them, fleeing from (being seen by) the people who might say, "This is Ayyoob"."
He also said, "Ayyoob used to take me via a route that was the longest and I would say "But this one is closer", He would reply, "I fear from (passing by these) gatherings". When he would pass by them and give salutations, they would reply to him with more than what he had greeted them, compared to others. So he would say, "O Allaah, you know that I did not desire this! O Allaah, you know that I did not desire this." (Ibn Sa'd, al-Fasawee)
Abu Zur'ah bin Abi Amr said, "ad-Dahhak bin Qays came out and made the prayer for rain with the people, but they were not granted rain, and nor did they see any clouds come. ad-Dahhaak said, "Where is Yazeed bin al-Aswad?" (And in a narration, "But nobody answered him!". He then said again, "Where is Yazeed bin al-Aswad al-Jurashee?" And I was resolute about him that if he was to hear my words he would get up.) Then he said, "Here I am". So he (ad-Dahhaak) said,"Stand and intercede with Allaah Azza wa Jall on our behalf, that he should grant us rain". So he stood up, made his face point in the direction of his feet, and made his head sink into his shoulders (out of humility). He then said, "O Allaah, these servants of yours sought intercession through me from you. So he had not called upon Allaah, three times, except that the people were granted rain in such abundance that they almost drowned on account of it. Then Yazeed said, "O Allah, this one made a show of me (i.e. ad-Dahhaak, by asking him and calling him out), so grant me freedom from this (fame)." Then he did not live except for the next Jumuah and then he passed away.