Why did around hundred and twenty thousand Companions (ṣaḥāba) leave Medina after the beloved Prophet (SAW) departed this world?
To answer this question we need to:
1. Understand the model of Islamic education (madraash) called Suffa established by the beloved Prophet (SAW)
2. Understand how Islam was propagated under the Four Rightly Guided Caliphs (al-Khulafāʾ al-Rāshidūn) of Abu Bakr As-Siddeeq (r), Umar ibn al-Khattab (r), Uthman ibn a-Affan (r) and Ali ibn Abu-Talib (r)
The caliphate of the Four Rightly Guided Caliphs (al-Khulafāʾ al-Rāshidūn) saw the expansion of the fledging Islamic State through newly liberated territories of the Byzantine and Sassanian Empires. Wherever Islam liberated, a student of Suffa was sent. This was in accordance with the methodology of the beloved Prophet (SAW) to send instructors from his circle of students to Arab & bedouin tribes and foreign kingdoms to teach the essence and fundamentals of Islam. The Prophet (SAW) educated his Companions (ṣaḥāba) with a firm Aqeedah and nurtured them mentally and spiritually within the hallowed grounds of Masjid-Nabawi on a raised platform called Suffa (located at the rear end of the mosque). Suffa could accommodate an estimated seventy permanent students, but the total number of students varied (including up to three-four hundred).
While ‘the emigrants’ (Muhajiroun) were engaged in trade and ‘the helpers’ (Ansar) worked the fields in agriculture, the Suffa ṣaḥāba were completely immersed in their studies while their welfare was attended to by the beloved Prophet (SAW) and other Companions (ṣaḥāba). However, the Suffa ṣaḥāba were never restricted to the study of Islamic knowledge only, as some participated in military campaigns and battles.
Throughout the caliphate of the Four Righly Guided Caliphs (al-Khulafāʾ al-Rāshidūn), a network of schools modelled on Suffa were established, overseen & taught by a prominent companion (ṣaḥāba) from the ranks of Ashab us-Suffa. An example is Abdullah Bin Mas’ud (r), the ṣāḥib most knowledgeable of the Qu’ran, who was sent by Umar ibn al-Khattab (r) to the city of Kufa to establish a circle of learning.
There were many Suffa model schools established, numbering greater than six in major cities during the caliphate of Umar ibn al-Khattab (r).
It this through the Suffa model that the Imams of the Four Schools of Jurisprudence (mathab) acquired Islamic knowledge (ilm) from teachers who studied under their teachers, with a chain that stretched to include a prominent ṣāḥib and concluded with the beloved Prophet (SAW).
Ibn ‘Abidin said:
The need for fiqh is like bread for people. The seed of this knowledge was sown by Ibn Mas’ud (r), who is considered one of the most outstanding jurists and scholars of the Companions. His disciple Alqama (r) watered this seed and made it a crop. His disciples, Ibrahim Nahai (r) cooked this crop and gathered the knowledge together. Hammad (r) threshed this crop and brought it to a state of threshing. Imam A’zam Abu Hanifa (r) brought this mixture to the state of flour i.e. he divided the science of fiqh into different parts. Imam Abu Yusuf made dough from it and Imam Muhammad baked it and delivered it to the people in the form of bread. This is the bread that people eat today. That is, by studying these sciences, they achieve the happiness of both worlds.”
Key Lesson: A person may be given iman but it is their responsibility and duty to strengthen it by carrying and upholding the dawah of the Prophet (SAW) by actively seeking knowledge, applying and teaching it.