It is narrated from Sayyiduna Zaid bin Khalid (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: "Whoever performs ablution and does it well, then prays two rak'ahs without being heedless in them, Allah will forgive all his past sins."
Hadith Referenceمسند احمد / مسند الشاميين / 17054
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد ضعيف لضعف هشام بن سعد