Bukhari

Hadith Commentary:
Semen is also produced in women, so why is nocturnal emission (ihtilam) impossible for them?
The relevance of this hadith to the chapter is as follows: Umm Salamah radi Allahu anha laughed, and the Prophet sallallahu alayhi wa sallam did not forbid her. In such situations, to laugh is a natural habit which is not blameworthy.

Hadith Commentary:
(1)
Islam commands us to avoid excess and deficiency in all matters and to adopt moderation. On occasions of happiness, it instructs us to smile rather than to laugh out loud. Nor does it tell us to always present ourselves as “frowning and grim-faced” (abūsan qamṭarīran).

(2)
Imam Bukhari rahimahullah has presented in these ahadith the manner of the laughter and smile of the Messenger of Allah sallallahu alayhi wa sallam. From all these ahadith, it is evident that the Messenger of Allah sallallahu alayhi wa sallam, in most situations of happiness or amazement, would suffice with a slight smile. Occasionally, he would laugh such that his front teeth became visible. Laughing excessively or rolling about while clapping hands is not liked in the Shariah, because it diminishes a person’s dignity. In this regard, the Messenger of Allah sallallahu alayhi wa sallam is the best example for us; his emulation should be adopted.

The Noble Qur’an has provided guidance in this matter in these words:
“They should laugh little and weep much.” ()
The Messenger of Allah sallallahu alayhi wa sallam said:
“Reduce your laughter, for excessive laughter causes the heart to die.” (Sunan Ibn Majah, Kitab al-Zuhd, Hadith: 4217)
Abu Hurairah radi Allahu anhu narrates that once the Messenger of Allah sallallahu alayhi wa sallam came to his noble companions while they were talking and laughing. He said:
“By Him in Whose hand is my soul! If you knew what I know, you would laugh little and weep much.” (Al-Adab al-Mufrad, Hadith: 284)