Is it obligatory to answer one who asks by God or by the Prophet, peace and blessings be upon him, such as "By the Prophet, you must do such-and-such," especially if these are common phrases not intended literally by the speaker? Does the ruling differ if the request is general in a post or video, such as its author saying, "By God or by the Prophet, peace and blessings be upon him, you must try such-and-such or do such-and-such"?

The command to give to one who asks by Allah and to fulfill an oath is on the basis of desirability, not obligation. The ruling varies according to the speaker's words and intention:

1. "I ask you by Allah" (سألتك بالله): If the swearer intends to make an oath for himself (and the "ba'" is for an oath), then this is a binding oath that is desirable to fulfill, unless it involves corruption. Expiation is upon the swearer if it is not fulfilled. If he intends to make someone else swear (and the "ba'" is for an oath for another), then this is a mere slip of the tongue (laghw), there is no oath in it, and nothing is binding upon the addressed person. If he intends request and supplication (and the "ba'" is for cause, not an oath), then this is seeking intercession and recourse through Allah to obligate the addressed person by Allah's right upon him. This is permissible, and responding to it is desirable, not obligatory.

2. "By the Prophet, do such and such" (والنبي تفعل كذا): If the swearer intends to make an oath for himself, or to make the addressed person swear, then this is swearing by other than Allah, which is forbidden, not binding, has no expiation, and does not require fulfillment. If he intends request and intercession by the right of the Prophet, peace be upon him, then this is permissible in dealings between creatures, and there is no oath involved. Responding to it is not obligatory, but one should be cautious about using this phrase so as not to fall into swearing by other than Allah.

3. Lapses (Laghw) in Oaths: This includes what a person utters in haste from oath-like phrases without intention, such as "No, by Allah," which is excused. One must be careful not to swear by other than Allah, even if by oversight or unintentionally, and those who do so should be reminded. The saying "By Allah, do such and such" in a non-serious context (like general requests online) is considered an excused lapse (laghw).