Ubayy bin Kaab reported,

Whenever the Messenger of Allah ﷺ supplicated for someone, he would begin with himself. One day he mentioned Musa and said, "May Allah's mercy be upon us and upon Musa. Had he been patient, Allah would have related to us more of his story, but he said, 'If I ask you about anything after this, do not keep me as a companion. You have already received from me an excuse'" [Kahf 18:76].

Ahmad 21126

Sahih

حدثنا يحيى بن آدم حدثنا حمزة بن حبيب الزيات عن أبي إسحاق عن سعيد بن جبير عن ابن عباس

عن أبي بن كعب قال

كان رسول الله ﷺ إذا دعا لأحد بدأ بنفسه فذكر ذات يوم موسى فقال رحمة الله علينا وعلى موسى لو كان صبر لقص الله تعالى علينا من خبره ولكن قال {إن سألتك عن شيء بعدها فلا تصاحبني قد بلغت من لدني عذرا}

أحمد 21126صحيح
Contents
Reference
Commentary
Ayat
Collection
Musnad Ahmad
Book
Abdullah bin Abbas from Ubayy bin Kaab
Numbering
Darussalam 21126
Ahmad 21126