Clarification that the smiling mentioned in the hadith: (Even if you meet your brother with a pleasant face) is specific to the same gender, namely

The Shaykh: However, it is necessary to mention on this occasion that this kindness mentioned by the Messenger (peace be upon him) in this hadith is by way of illustration, namely his saying: and that other hadith explains it: . We must note here that this matter should be restricted to the same gender, meaning that a man meets his male brother with a pleasant and smiling face as we mentioned, and likewise a woman meets her female sister with a pleasant and smiling face. But it is not permissible to practice this Sunnah between the two genders, and in reality, this is something in which people have suffered from negligence or laxity in observing this distinction that we have pointed out. Most Muslims today, men and women, have fallen into this, and women have exceeded men in this regard. For we often hear a woman intentionally smiling, or even laughing, or even giggling while talking to a man. This is certainly not of kindness in any way, but rather it is of the evil that we can consider a type of zina, as he (peace and blessings be upon him) said in the authentic hadith: . The Messenger (may Allah’s prayers and peace be upon him) mentioned these types of zina only because they are preliminaries to the major sin, and he pointed to that at the end of that hadith by saying: . So in this hadith is the prohibition of means that may lead to a bad outcome, and whose outcome is deviation, corruption, and open sinfulness. The Messenger (peace and blessings be upon him) mentioned these types in this hadith not by way of exhaustive listing, meaning these are not the only means that are prohibited for fear that they will lead their owner to the major sin, but rather the Messenger (peace be upon him) mentioned these types of means by way of illustration, not by way of limitation. And from the understanding of this hadith in text and derivation, Shawqi, a famous Egyptian poet, took his saying:
"A glance, then a smile, then a greeting *** then speech, then an appointment, then a meeting"
Here he used a word not mentioned in this hadith, where he said: A glance, then a smile. It was not mentioned in the previous hadith: to the end. The Messenger (peace be upon him) did not mention the glance, nor did he mention the smile. The reason is what I hinted at earlier, that those types mentioned by the Messenger (peace be upon him) in the hadith were not mentioned by way of exhaustive listing, but by way of illustration. Otherwise, Shawqi’s saying: "A glance" is attested by his saying (peace and blessings be upon him): and another hadith in which the Messenger (peace be upon him) was asked about the sudden glance, meaning a man’s gaze falls on the features of a woman, and vice versa, a woman’s gaze falls on the beauty of a man. He said (peace be upon him): The first glance is for you, and the second is upon you. The first glance is the sudden glance, and if the looker continues with it, it becomes a second glance because he did not avert it. And from here Shawqi said what he said:
"A glance, then a smile, then a greeting *** then speech, then an appointment, then a meeting"
The point is that this charity mentioned by the Messenger (peace be upon him) in this hadith is also by way of illustration, not limitation, namely his saying: is specific to the same gender with the same gender, not the same gender with the opposite gender, for fear that it may be a key to evil. This is a reminder, and the reminder benefits the believers.