Continuation of the benefits of the hadith regarding the wealth of Bahrain.

The Shaykh : And among the benefits of this hadith is the good character of the Messenger (peace and blessings be upon him) when he smiled upon seeing them. They came looking eagerly for the wealth, and this is undoubtedly among the best of character. Some people, when they see a person looking eagerly to ask for something, find themselves disgusted; they are disgusted and frown, saying to themselves, "Oh, this person is selling himself." But the Messenger (peace and blessings be upon him), when he saw them, kept smiling (peace and blessings be upon him). It also contains that it is recommended for a person to convey glad tidings to people, because of the joy it brings to them. And whatever brings joy to your brother, you count it as a reward with Allah for you in it, in His saying: . It also contains in the hadith the permissibility of swearing an oath without being asked to do so. Where is this taken from? Where is it taken from in the hadith regarding the permissibility of swearing an oath without being asked? It is not in Sahih al-Bukhari.
It is not in Sahih al-Bukhari.
The reader: It is taken from his saying:

The Shaykh : From his saying: And it contains a warning against the worldly life, due to his saying (peace and blessings be upon him): .