What is prescribed when meeting is to say salaams and shake hands. If a person has come from a journey then it is prescribed to embrace him. As for kissing at every meeting, this is not part of the Sunnah of greeting, rather it is narrated that this is disallowed. Al-Tirmidhi narrated (2728) that Anas ibn Maalik (may Allaah be pleased with him) said: A man said: O Messenger of Allaah, when one of us meets his brother or his friend, should he bow to him? He said: No. He said: Should he embrace him and kiss him? He said: No. He said: Should he take his hand and shake hands with him? He said: Yes. This hadeeth was classed as hasan by al-Albaani in Saheeh Sunan al-Tirmidhi. 

Yes, kissing is prescribed on some occasions, when returning from a journey and the like. See question no. 34497. 

But as for exchanging kisses every morning, there is no doubt that this is not prescribed, and it is a strange phenomenon that is alien to Muslim societies. There is the fear that it may be taken as a means by those in whose hearts is a disease to engage in haraam physical pleasure within the framework of another phenomenon which is called admiration, which is undoubtedly a haraam kind of infatuation. 

Al-Nawawi (may Allaah have mercy on him) said: 

As for embracing and kissing the face of someone other than a person who has returned from travelling, etc – apart from a child – this is makrooh, as was clearly stated by al-Baghawi and others… As for a handsome beardless youth, it is haraam to kiss him under any circumstances, whether he is returning from a journey or not. It seems that embracing him is akin to kissing him, whether the one who is kissing or the one who is kissed are righteous or otherwise. End quote from al-Majmoo’, 4/477 

The scholars of the Standing Committee for Issuing Fatwas were asked: There is the phenomenon of young men kissing one another on the cheeks every time they meet, every day. This phenomenon has also spread among old men, in the mosques and in the classrooms. Is this contrary to the Sunnah or is there nothing wrong with it? Is it a bid’ah or a sin or is it permissible? 

They replied: 

What is prescribed when meeting is to say salaam and shake hands, If the meeting is after a journey then it is prescribed to embrace as well, because it is narrated that Anas (may Allaah be pleased with him) said: When the companions of the Prophet (peace and blessings of Allaah be upon him) met, they would shake hands, and if they had come from a journey they would embrace. As for kissing the cheeks, we do not know of any Sunnah to indicate that. End quote. 

Fataawa al-Lajnah al-Daa’imah, 24/128 

Shaykh al-Albaani (may Allaah have mercy on him) said in Silsilat al-Ahaadeeth al-Saheehah (1/74, hadeeth no. 160): This is the hadeeth of al-Tirmidhi that we mentioned at the beginning of our answer: 

In fact the hadeeth clearly states that kissing when meeting is not prescribed in Islam. That does not include kissing one's children or wife, as is obvious. 

With regard to the ahaadeeth which state that the Prophet (peace and blessings of Allaah be upon him) kissed some of his companions on various occasions – such as when he kissed and embraced Zayd ibn Haarithah when he came to Madeenah, and when he embraced Abu’l-Haytham ibn al-Tayhaan, etc – the following points may be noted in response to that: 

1 – These are unsound ahaadeeth which cannot be taken as evidence. 

2 – Even if any of them were saheeh, it is not permissible to use them against this saheeh hadeeth, because it is an action on the part of the Prophet (peace and blessings of Allaah be upon him) which may be interpreted as applying to a specific case or there may be some specific reason for that which makes this hadeeth unfit to be used as evidence, unlike this hadeeth, which is a verbal hadeeth that is addressed in general terms to the ummah as a whole, so it is string evidence which cannot be rejected. It is established in the field of usool that words take precedence over deeds in the event of a conflict, and the hadeeth which indicates a prohibition takes precedence over another which indicates permissibility. This hadeeth is verbal and indicates a prohibition, so it takes precedence over the other ahaadeeth mentioned even if they are saheeh. 

Similarly, with regard to hugging and embracing, we say that it is not prescribed because the hadeeth forbids it, but Anas (may Allaah be pleased with him) said: When the companions of the Prophet (peace and blessings of Allaah be upon him) met, they would shake hands, and if they had come from a journey they would embrace Narrated by al-Tabaraani in al-Awsat, and its men are the men of saheeh, as stated by al-Mundhiri (3/270), and al-Bayhaqi, 8/36 

Al-Bayhaqi (7/100) narrated with a saheeh isnaad from al-Sha’bi that when the companions of Muhammad (peace and blessings of Allaah be upon him) met, they would shake hands, and when they came from a journey they would embrace one another. 

Al-Bukhaari narrated in al-Adab al-Mufrad (970), and Ahmad narrated (3/495) that Jaabir ibn ‘Abd-Allaah said: I heard that a man knew a hadeeth and had heard it from the Messenger of Allaah (peace and blessings of Allaah be upon him). I bought a camel, loaded my luggage onto it, and traveled for a month until I came to Syria, where I found ‘Abd-Allaah ibn Unays. I said to the doorkeeper: Tell him: Jaabir is at the door. He said: Ibn ‘Abd-Allaah? I said: Yes. He came out tripping on his garment and he embraced me and I embraced him… Its isnaad is hasan as stated by al-Haafiz, 1/195. al-Bukhaari narrated it among the mu’aalaq reports. 

So it may be said that embracing in the case of a journey is exempted from the prohibition, because the Sahaabah did that. End quote. 

And Allaah knows best.