It is permissible
for the Imam and Ma’mums (persons being led by an Imam in Prayer) to supplicate for themselves in the singular mode, such as by saying: O My Lord! Forgive me; have mercy upon me; guide me; grant me health; support me; and grant me sustenance.
The Prophet (peace be upon him) taught
Abu Bakr Al-Siddiq (may Allah be pleased with him) to say in his Salah: “Allahuma ini zhalamtu nafsi zhulman kathiran wa la yaghfir al-dhunuba ila anta faghfir li maghfiratan min ‘indika warhamni inaka anta Al-Ghafur Al-Rahim [O Allah! I have done many injustices to myself (by committing many sins), and no one forgives sins except You. Grant me forgiveness from You and have mercy on me, for You are the Oft-Forgiving, the Most Merciful].”
The Prophet (peace be upon him) advised
Mu‘adh (may Allah be pleased with him) to say after finishing every Salah: “Allahuma a‘ini ala dhikrika, wa shukrika, wa husni ibadatika [O Allah! Help me remember You, thank You and worship You in the best manner].”
The Prophet (peace be upon him) used to say while in Sujud:
“Allahuma ighfir li dhanbi kullahu, diqahu wa jilahu, wa awalahu wa akhirahu, wa ‘alaniyatahu wa sirrahu [O Allah forgive me all my sin, small and great, first and last, open and secret].”
But if the Imam is supplicating out loud for himself and for others in Qunut (supplication recited while standing after bowing in the last unit of Prayer), or while invoking Allah during Friday Khutbah (sermon), he should not supplicate to Allah for himself only while ignoring the others. Rather, they should supplicate in the plural mode for everybody. Imam
Al-Tirmidhy related on the authority of
Thawban (may Allah be pleased with him) that the Prophet (peace be upon him) said:
“It is not lawful for a person to look into the inside of a person’s house until he seeks permission; if he looks, he has let himself in (without permission). (Part No. 5; Page No. 309) Nor leads people in Salah (Prayer) and make a supplication to Allah specifically for himself, without (including) them; if he does so, he has betrayed them. Nor stand for Salah while suppressing an urge to urinate/defecate.”
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.