The evidence that the two rak'ahs of Dhuha are a recommended practice every day.

The Shaykh : It also contains evidence that the two rak'ahs of Dhuha are a recommended practice every day, because if you have a charity due for every one of your limbs, and the two rak'ahs suffice for it, this implies that the Dhuha prayer is a recommended practice every day in order to fulfill the charities that are due from you. The scholars said that the time for the Dhuha prayer begins when the sun has risen the height of a spear, meaning approximately one-quarter to one-third of an hour after sunrise, until just before the midday prayer, or until ten minutes before the midday prayer. All of this is the time for the Dhuha prayer. You may pray the two rak'ahs of Dhuha at any time between the sun rising the height of a spear and the sun reaching its zenith, and it will suffice. However, it is better to pray it at the end of the time, based on the saying of the Prophet (peace and blessings be upon him) , meaning when the camels rise from the scorching heat of the sand due to its intense heat. For this reason, the scholars said that delaying the two rak'ahs of Dhuha to the end of the time is better than advancing it, just as the Prophet (peace and blessings be upon him) preferred delaying the 'Isha' prayer to the end of its time, except in cases of hardship. In conclusion, Allah has opened for the person many doors and paths to good, and whatever a person does from these paths, the good deed is multiplied tenfold, up to seven hundredfold, up to many multiples. And success is from Allah.
The reciter: Praise be to Allah, Lord of the worlds, and may peace and blessings be upon our Prophet Muhammad, and upon his family and all his Companions.