The answer: Someone may say, I shall insult or beat him, or at least I shall not greet him…
So what if Allah, the Almighty, who is greater than our fathers and any other creature, is the one being insulted?!
That's why Muslims don't greet the Jews and the Christians. We believe that you insulted Allah, the Almighty, when saying that He has a son, by the doctrine of Trinity, and by claiming that God can be struck and spit on the face!!!
This is mentioned in Mathew 26:67:
67 Then they spit in his face and struck him. And some slapped him,68 saying, “Prophesy to us, you Christ! Who is it that struck you?”
According to our belief, this is considered insulting Allah, the Almighty, and this is proved by the following:
1 – The Correct Bukhari, no. 6830, Abu Musa Al Ashaari narrated that the prophet (PBUH) said: "None is more patient than Allah against the harmful and annoying words He hears (from the people): They ascribe children to Him, yet He bestows upon them health and provision ".
2 – The Correct Bukhari, no. 4592, Abu Huraira narrated that the prophet (PBUH) said: "Allah said: 'The son of Adam tells a lie against Me, though he hasn't the right to do so. He abuses me though he hasn't the right to do so. As for his telling a lie against Me, it is his saying that I will not recreate him as I created him for the first time. In fact, the first creation was not easier for Me than new creation. As for his abusing Me, it is his saying that Allah has begotten children, while I am the One, the Self-Sufficient Master Whom all creatures need, I beget not, nor was I begotten, and there is none like unto Me".
As for the Jews insulting Allah, the Almighty, it's mentioned in the Quran in two positions:
1 – Allah, the Almighty, says quoting the Jews: {And the Jews say, "The hand of Allah is chained." Chained are their hands, and cursed are they for what they say. Rather, both His hands are extended; He spends however He wills} (The Table Spread with Food:64).
2 – Allah, the Almighty, says quoting them: {Allah has certainly heard the statement of those [Jews] who said, "Indeed, Allah is poor, while we are rich." We will record what they said and their killing of the prophets without right and will say, "Taste the punishment of the Burning Fire} (The Family of Imran:181).
In the Jalalen Interpretation: Those were the Jews, they said so when Allah, the Almighty, revealed the verse: {Who is it that would loan Allah a goodly loan so He may multiply it for him many times over?}. They said: If Allah was rich, He wouldn't ask us for a loan.
I have a question here: Isn't this an insult for Allah, the Almighty, that makes us, Muslims, don't greet them?!
In general, Allah, the Almighty, says: {The Jews say, "Ezra is the son of Allah "; and the Christians say, "The Messiah is the son of Allah." That is their statement from their mouths; they imitate the saying of those who disbelieved [before them]. May Allah destroy them; how are they deluded?} (The Repentance:30).
Isn't this an insult to Allah, the Almighty, according to our belief?!
The answer: It is, though it is permissible to greet the Jews and the Christians with words like: hello, good morning, how are you, welcome,…..etc.
Another reason for not greeting the Jews and the Christians with "peace be upon you" is because Allah, the Almighty, informed His prophet (PBUH) that those Jews and Christians would never be satisfied with Muslims till they believe in their beliefs. Besides, this is a proof for the believers' truthfulness, as "peace (al salam)" is one of Allah's names. That's why paradise was called "the house of peace", and the prophet (PBUH) used to say to his companions: "Peace be upon those who follow guidance", meaning that if you follow truth, you will be in peace…
In addition to this, not greeting them saying "peace be upon you" doesn't mean not saluting them, and asking about them, but we preserve their rights, as Allah, the Almighty, says: {Allah does not forbid you from those who do not fight you because of religion and do not expel you from your homes - from being righteous toward them and acting justly toward them. Indeed, Allah loves those who act justly} (The Woman to be Examined:8).
Third: Someone may say: there's a speech that clarifies how racist Muhammad was, it's mentioned in The Correct Bukhari, no. 5788. Anas Ibn Malek narrated that the prophet (PBUH) said: " If the people of the Scripture (the Jews and the Christians) greet you, then you should say (in reply), 'Wa'alaikum (And on you) ".
I say: this speech has a special reason. It's that the Jews said to the prophet (PBUH): "Assaamo alaikom", it's same as "Assalamo Alaikom" but without "l", which means in Arabic: "death be upon you". So, he (PBUH) recommended to his companions to reply to the Jews who greet them saying : "And upon you". This is proved in the following:
1 – The Correct Bukhari, no. 6414, Anas Ibn Malek narrated that a Jew passed by the prophet (PBUH) and said: "Assamo Alaika (death be upon you)." The messenger of Allah (PBUH) said in reply, "Wa Alaika (and upon you)". The messenger of Allah (PBUH) then said to his companions, "Do you know what he (the Jew) has said? He said: "Assamo Alaika.'" They said, "O messenger of Allah! Shall we kill him?" The prophet (PBUH), said, "No. When the people of the Book greet you, just say: "Wa Alaikum (and on you)".
2 – Ibn Majah's Sunan, no.4530, Abdullah Ibn Omar narrated that the prophet (PBUH) said: "When the Jews greet you, they usually say: "Assamo alaikum (Death be on you)", so you should say (in reply to them): "Wa alaikum (And on you)".
Therefore, he (PBUH) ordered to reply to the Jews' greeting saying "and on you", as they usually don't say "peace be upon you", and Allah, the Almighty, says in the Quran: {And when you are greeted with a greeting, greet [in return] with one better than it or [at least] return it [in a like manner]. Indeed, Allah is ever, over all things, an Accountant} (The Women:86).
Al Qurtubi said in his interpretation: the greeting is peace, it's asking Allah good life for you. Ibn Abbas said: the verse means that if you, Muslims, are greeted with a greeting from a believer " greet in return with one better than it", and if you are greeted with a greeting from a disbeliever "return it".
Fourth: Someone may ask: what’s the meaning of those words "and when you meet any one of them on the roads force him to go to the narrowest part of it"?
I say: There are many interpretations for the scholars concerning those words:
1 – Al Qurtubi said those words mean that when you, Muslims, meet them on a narrow road, get aside for them to pass. So, this meaning is suitable for the first sentence in the speech, and those words don't mean that when you meet them in a wide road, force them to get to its narrow edge as a kind of annoying them, because Muhammad (PBUH) prohibited us from annoying non-Muslims without any reason.
2 – The author of (Aon Al Maabood Fi Sharh Sunan Abu Dawood) said: If the road is crowded with Muslims, ask the Jews to get aside, but if the road is empty, don't ask them to do so.
3 – Ibn Al Othaimein said: those words mean that if you, Muslims, meet the Jews in a road, don't get aside for them, so that you walk in the narrowest part of the road, but go on your way, and let them go to the narrowest part of the road. It's well-known that the prophet (PBUH) never forced a Jew (living in Madina) to go to the narrowest part of the road, nor did his companions. So, this means: when you meet Jews in a road, don't scatter your group to let them pass, but walk on your way and don't get aside. This speech doesn't abhor people from Islam, it rather shows the Muslim's pride, and that a Muslims doesn't condescend himself for anyone, except for Allah, the Almighty.