The Messenger of Allah ﷺ said, "Whoever is diligent in praying the two units of Duha will have his sins forgiven, even if they are like the foam of the sea."
حدثنا وكيع قال حدثنا النهاس بن قهم الصبحي عن شداد أبي عمار
قال رسول الله ﷺ من حافظ على شفعة الضحى غفرت له ذنوبه وإن كانت مثل زبد البحر
Its isnad is daif because of Nahhas. Tirmidhi transmitted it through his route (2/341, no. 476), noting its rarity, as did Ibn Majah (1/440, no. 1382). The hadith itself is sahih, transmitted by Bukhari in the chapter on shortening prayer (12) and in the chapter on adhan (41), and by Muslim in the chapter on travelers (78, 80).