The Prophet (blessings and peace of Allah be upon him) was very keen to teach and educate his ummah, and he used various educational methods to communicate information soundly. In this hadith, he teaches us the etiquette of speaking and greeting. ‘Abdullah ibn ‘Umar ibn al-Khattab (may Allah be pleased with him) narrated that when the Prophet (blessings and peace of Allah be upon him) greeted someone with salaam, he would greet him three times, and perhaps this refers to his practice when greeting a large number of people who would not all hear a greeting given once, or it was his practice to make sure that they heard the second and third greetings if he thought that the first one had not been heard, or he would repeat the salaam because he wanted to seek permission to enter, if the first salaam was not heard or responded to. But if he passed by a gathering and greeted everyone present, or he came to a house and gave the greeting of salaam and they responded, then there was no point in repeating it. It may be that when he came to some people, he would give the greeting of salaam by way of seeking permission to enter, then when he entered the house, he would greet them with salaam, then when he got up to leave the gathering he would say salaam to bid farewell, which is like a supplication (dua). If he uttered a sentence, he would repeat it three times, so that those who were present would understand it and comprehend its meaning, because repetition was most effective in helping people to remember and making the pronunciation clear, so that there would be no room for misinterpretation, especially if there was the fear that his words might not be understood or heard, or if he wanted to convey the message when he was teaching, rebuking or exhorting. This is one of the basic principles of teaching in Islam, because repeating something three times is sufficient to make the meaning clear and leave no excuse for anybody. The Prophet (blessings and peace of Allah be upon him) used to always do that in his actions too, so that his ummah could emulate him and so as to be an example for others..