What is the ruling on supplicating in the plural form during prostration when praying alone, such as saying: "O Allah, indeed You are Pardoning and Generous, You love pardon, so pardon us. O Allah, O Stabilizer and Changer of hearts, stabilize our hearts upon Your religion. O Allah, grant us success in what You love and are pleased with"?

It is common to use the plural form of supplication when prostrating oneself, even if one is praying alone. The Prophet (peace and blessings be upon him) was reported to have supplicated in both plural and singular forms while prostrating, such as his saying: "Glorified are You, O Allah, our Lord, and with Your praise; O Allah, forgive me."

The supplications mentioned in the question are not reported to have been recited during prostration, but there is no harm in reciting them occasionally, for the Prophet (peace and blessings be upon him) said: "The closest a servant is to his Lord is while he is prostrating, so increase your supplications."

An individual should strive to use the exact wording of the reported supplications. Thus, what has been reported in the plural form should be recited in that form, even if the supplicant is alone, and what has been reported in the singular form should be recited in that form.