عن أبي أيوب الأنصاري قال جاء رجل إلى النبي صلى الله عليه و سلم فقال عظني وأوجز فقال : إذا قمت في صلاتك فصل صلاة مودع ولا تكلم بكلام تعتذر منه غدا واجمع الإياس مما في يدي الناس (مسند احمد)

Hadrat Abu Ayub R.A. narrates that a person came to Rasulullah Salallahu Alaihi Wasallam and said, “Advise me but let it be concise.” Rasulullah Salallahu Alaihi Wasallam said, “When you stand for Salaah then perform Salaah like a person bidding farewell (to everything besides Allah Ta'ala), and don’t utter such words for which you will have to present an excuse tomorrow (on the day of Qiyaamah), and make a firm determination to be despondent (not to desire) of what people possess.”

One meaning of “Perform Salaah like a person bidding” is the meaning included with the translation above, that is, perform Salaah in a manner that your heart is free from material things, and your focus is only towards Allah Ta'ala. The second possible meaning is this, perform Salaah like a person that knows that this is his last and final Salaah, after which he will be leaving the world without having another opportunity to perform Salaah. With what concentration wouldn’t such a Salaah be performed! Logically speaking, this thought is possible in every Salaah, as no person knows whether he will have the opportunity of performing the next Salaah or not. Therefore, consider every Salaah as one’s final Salaah of his life, with the thought that perhaps I will not live till the next Salaah. In this way, a person will attempt performing an excellent Salaah.

The second advice is to ponder a little before speaking, as a person has the choice of refraining from speaking, if he hasn’t spoken as yet. However, if he has spoken and it happens to incorrect, then he will be shameful over his words and will also have to present excuses. 

The third advice is to end the desire and hopes of the material possession of the wealthy. (Mazaahir-e-Haq)