What are the names of the Companions who remained behind from the Battle of Tabuk, and what are the most prominent benefits and lessons derived from the account of their repentance?

The three who lagged behind the Battle of Tabuk were Ka'b ibn Malik, Murarah ibn al-Rabi' al-'Amri, and Hilal ibn Umayyah al-Waqifi, all of whom were from the Ansar. Among the benefits derived from Ka'b's narration are: the permissibility of raiding during the sacred month, the obligation to mobilize when the Imam calls the army to arms, that one who is unable to go forth is excused, the gravity of sin, the permissibility of praising a person for the good qualities they possess if temptation is safeguarded against, the permissibility of wishing for good that has been missed, the permissibility of withholding greetings and shunning a sinner for more than three days, and that charity is a means of salvation.