Allah's Messenger said: "Whoever continuously performs the two Rak'ah of Ad-Duha his sins will be forgiven, even if they be like the foam of the sea."
Jami` at-Tirmidhi Book 3, Hadith 24
← Previous Hadith Allah's Messenger narrated that Allah, Blessed and Most High said: "Son of Adam: Perform four Rak'ah for Me in the beginning of the day it will suffice you for the latter part of it."

Jami` at-Tirmidhi Book 3, Hadith 23 Next Hadith → "The Prophet would pray Ad-Duha until we would say: 'He will not leave it.' And he would leave it until we would say: 'He will not pray it.'"

Jami` at-Tirmidhi Book 3, Hadith 25