No Muslim person who, when an obligatory prayer becomes due, perfects its ablution, humility, and bowing except that it becomes an expiation for the sins that preceded it as long as he has not committed a major sin, and this applies to all times
‘Uthmān (may Allah be pleased with him) reported that he heard the Messenger of Allah (may Allah's peace and blessings be upon him) say:
"No Muslim person who, when an obligatory prayer becomes due, perfects its ablution, humility, and bowing except that it becomes an expiation for the sins that preceded it as long as he has not committed a major sin, and this applies to all times."
The Prophet (may Allah's peace and blessings be upon him) clarified that no Muslim who, when the time for an obligatory prayer becomes due, perfects and completes its ablution, then prays with humility in such a way that his heart and all of his body organs are devoted to Allah and heedful of His greatness, and he perfects the acts of prayer like bowing, prostration and other actions, except that this prayer will serve as an expiation for the preceding minor sins as long as he has not committed a major sin; and this merit applies to all times and every prayer.
Lessons
The prayer that expiates sins is that in which one perfects its ablution and performs it with humility and which is fully devoted to Allah Almighty.
The merit of performing acts of worship regularly and that these are a means of forgiving minor sins.
The merit of perfecting ablution and excellently performing prayer with humility.
The importance of avoiding major sins to have the minor sins forgiven.
Major sins are forgiven only through repentance.
Explanation in Arabic
بَيَّنَ النبيُّ صلى الله عليه وسلم أنَّه ما مِن مُسلم يَدخل عليه وقت الصلاة المفروضة فيحسن وضوءها ويُتِمُّه، ثم يَخشع في صلاته بحيث يكون قلبُه وجوارحُه كلُّها مُقبلةً على الله مستحضرةً عظمتَه، ويُتم أفعالَ الصلاةِ كالركوعِ والسجود وغيرِهِ، إلا كانت هذه الصلاةُ مُكفِّرَةً لما قبلها من المعاصي الصغائر، ما لم يعمل كبيرة من كبائر الذنوب، وهذا الفضل مُمْتَدٌّ على مَرِّ الزمان وفي كل صلاة.
الصلاة المكفرة للذنوب هي التي أحسن العبد وضوءَها، وأدَّاها خاشعًا يبتغي بها وجه الله تعالى.
فضل المداومة على العبادات، وأنها سبب لمغفرة صغائر الذنوب.
"إذا توضأ العبد المسلم - أو المؤمن- فغسل وجهه، خرج من وجهه كل خطيئة نظر إليها بعينيه مع الماء، أو مع آخر قطر الماء، فإذا غسل يديه، خرج من يديه كل خطيئة كان بطشتها يداه مع الماء، أو مع آخر قطر الماء، فإذا غسل رجليه…
"There is no Muslim who performs ablution well and then stands and prays two Rak‘ahs while focused on them with his heart and his face, except that Paradise will be guaranteed for him." I said: "What a fine thing this is!" Thereupon, I heard someone in front of me saying: "What he said before it…
Humrān, the freed slave of 'Uthmān ibn' Affān, reported that he saw 'Uthmān ibn' Affān asking (for water) to perform ablution, and he poured water from his vessel over his hands and washed them thrice and then put his right hand in the water and rinsed his mouth and washed his nose by putting water…