Allah Almighty says: {And those who came after them say, “Our Lord, forgive us and our brethren who preceded us in faith} [Surat al-Hashr: 10] And He says: {and seek forgiveness for your sins and for the [the sins of] the believing men and women} [Surat Muhammad: 19] Allah Almighty also says that Ibrāhīm (peace be upon him) said: {Our Lord, forgive me, my parents, and the believers on the Day when the reckoning will take place.} [Surat Ibrāhīm: 41]
1) The verses highlight the virtue of supplication for the believers in their absence, as it is one of the ways for having one’s supplications answered.
2) Supplicating for the believers is a right which a believer owes his fellow believers.
1494/1- Abu ad-Dardā’ (may Allah be pleased with him) reported that he heard the Prophet (may Allah’s peace and blessings be upon him) say: “There is no Muslim slave who supplicates for his brother in his absence except that an angel says to him: ‘May the same be for you.’” [Narrated by Muslim]
1495/2- He also reported that the Prophet (may Allah’s peace and blessings be upon him) used to say: “The supplication of a Muslim for a fellow Muslim in his absence is answered. There is an entrusted angel At his head; whenever he invokes good for his brother, the entrusted angel says, “Āmīn (Amen), and likewise to you.” [Narrated by Muslim]
1) It is recommended for a Muslim to supplicate for himself and for his Muslim brothers to obtain what is good in the worldly life and in the Hereafter.
2) Supplication for others in their absence is one of the readily answered supplications.
3) Supplication for other Muslims in their absence indicates the truthfulness of faith, the continuity of their mutual love, and guarding the right of brotherhood.