Hadith Q1225
وَالْبَيَانِ أَنَّ رَكْعَتَيِ الضُّحَى تُجْزِئُ مِنَ الصَّدَقَةِ الَّتِي كُتِبَتْ عَلَى سُلَامَى الْمَرْءِ فِي كُلِّ يَوْمٍ
And the statement that two rak'ahs of Duha suffice for the charity that is obligatory every day upon the human joints.
Hadith 1225
Sayyiduna Abu Dharr (may Allah be pleased with him) narrates from the Noble Prophet (peace and blessings be upon him) that he (peace be upon him) said: "When any one of you wakes up in the morning, charity is due on every joint of his body. So, every utterance of 'La ilaha illallah' « لَا إِلٰهَ إِلَّا اللهُ », every 'Alhamdulillah' « الحَمْدُ لِلَٰهِ », every 'Allahu Akbar' « اللَٰهُ أَكْبَرُ », and every 'Subhanallah' « سُبْحَانَ اللهِ » becomes charity. Enjoining good and forbidding evil also becomes charity. And all of these are sufficed by offering two rak‘ahs of Duha (forenoon) prayer."