Is the prayer valid in undergarments if there is something on the shoulder while most of the shoulder is exposed?

Question:
Honorable Shaykh, may Allah grant you success, he says: Is the prayer in undergarments valid if there is something on the shoulder while most of the shoulder is exposed?

Answer:
Covering the shoulder is not obligatory except according to a narration from Imam Ahmad; otherwise, it is not obligatory. As long as the garment stays on his 'awrah (part of the body that must be covered), he is not required to put something on his shoulder. This is only a matter of what is recommended (mustahabb) according to the majority.