Career
lieutenant is said Muhammad informed Muadh that on his return to Medina, he will perhaps see only his Masjid and grave. Upon hearing this, Muadh began to cry. When Muadh returned to Medina, the Khalifa (Head of state) was Abu Bakr.
Mu'adh ibn Jabal said that Muhammad said: "The People of Paradise will not regret except one thing alone: the hour that passed them by and in which they made no remembrance of Allah." Narrated by Bayhaqi in Shu'ab al-iman (1:392 #512-513) and by Tabarani.
Haythami in Majma al-Zawa"id (10:74) said that its narrators are all trustworthy (thiqat), while Suyuti declared it hasan in his Jami' al-saghir (#7701). Pray the prayer of he who is just about to leave and imagine that you might not be able to pray ever again.
Know that the believer dies between two good deeds. One that he performed and one that he intended to perform later on." quote taken from Siffat as Safwah
The college for the study of Shariah law at Mosul University under the Islamic State is named after Mu'adh ibn Jabal.