Hafiz Muhammad Ameen
(1) Ibn Abbas (radi Allahu anhu) was an extremely intelligent person. He raised this subtle point: if someone can become a Muhajir (emigrant) by leaving his home and belongings, then those Ansar who reached Makkah to pledge allegiance were also Muhajirun, because they left Madinah and came to you, and at your command, they came to Madinah twice. Similarly, the Muhajirun can also be called Ansar (helpers), because they supported you at every opportunity and assisted you. And those who help, according to the language, can be called Ansar. This is merely a point of nuance; otherwise, the reality is that the Muhajirun were those who left their homes and belongings forever. Even when Makkah was conquered and became Dar al-Islam, they did not prefer to stay there. And the Ansar were those who offered their city, their homes, their lands, their properties, even their lives to the Messenger of Allah (sallallahu alayhi wa sallam). Radi Allahu anhum wa ardahum.
(2) "The Night of Aqabah"—in reality, this refers to two nights. One was in the 11th year of Prophethood, which is called Laylat al-Aqabah al-Ula (the First Night of Aqabah), and the other in the 13th year of Prophethood, which is called Laylat al-Aqabah al-Thaniyah (the Second Night of Aqabah). Aqabah is the name of the last mountain pass from Mina towards Makkah. Near this Jamrah, the Messenger of Allah (sallallahu alayhi wa sallam) invited the people of Madinah to Islam; this was in the 11th year of Prophethood. There were six men, and they promised to meet you the following year and, upon returning to Madinah, presented your message to the people there. In the 12th year of Prophethood, after Hajj, twelve men met you at this Jamrah, accepted Islam, and pledged allegiance to you. You sent a preacher with them. The following year, in the 13th year of Prophethood, after Hajj, more than seventy (70) Ansar pledged allegiance to you at the same Jamrah and requested you to come to Madinah. You accepted this and, at the appropriate time, proceeded to Madinah al-Munawwarah.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 4171