Chapter: 87, Verse: 15

علي بن محمد، عن أحمد بن الحسين، عن علي بن الريان، عن عبيد الله بن عبدالله الدهقان قال: دخلت على أبي الحسن الرضا (عليه السلام) فقال لي: ما معنى قوله: " وذكر اسم ربه فصلى " قلت: كلما ذكر اسم ربه قام فصلى، فقال لي: لقد كلف الله عزوجل هذا شططا فقلت: جعلت فداك فكيف هو؟ فقال: كلما ذكر اسم ربه صلى على محمد وآله

The narrator says,

I visited Abu al-Hasan al-Rida (عليه السلام), and he said to me: "What is the meaning of His statement:

'And he mentions the name of his Lord and prays' (87:15)?"

I (the narrator) said: "Whenever he mentions the name of his Lord, he stands up and offers the ritual prayer."

The Imam said to me: "Allah (عز وجل) would have imposed an excessive burden if that were the case."

I (the narrator) said: "May I be sacrificed for you, then what does it mean?"

The Imam said: "Whenever he mentions the name of his Lord, he sends blessings upon Muhammad (S) and his family (Salawat)."

[Source: al-Kafi, Vol. 2, Pg. 494, Hadith. 18]