The reason the author cited the hadith of "whoever does a good deed to someone"

The questioner:
He says: Honorable Shaykh, may Allah grant you success, is it not said that the author also cited the hadith of "whoever does a good deed to someone"?

The Shaykh:
Where?

The questioner:
That he cited it.

The Shaykh:
A connection appears to us, but he may have had a connection that did not appear to us; Allah knows best. The author is a great imam, a distinguished scholar; he may have had something that did not appear to us; Allah knows best. Yes.

The questioner:
He says: Honorable Shaykh, may Allah grant you success, is it not said that the author also cited the hadith of "whoever does a good deed to someone"?

The Shaykh:
Yes.

The questioner:
That he cited it because one who swears to reciprocate the good deed done to him, and states that if he prays for him he will reciprocate, does not break his oath?

The Shaykh:
That is far-fetched, and the hadith does not indicate that. Yes.