Is it permissible to recite the morning and evening adhkar (remembrances) in the plural form with the intention that their benefit extends to the reciter and his family members who do not observe them?

One should recite the invocations (adhkar) in the exact form reported from the Prophet, peace and blessings be upon him, whether they are in the plural form, such as "O Allah, by You we have reached morning..." or in the singular form, such as "O Allah, I ask You for pardon and well-being...". The Sunnah (definition) emphasizes the importance of adhering to the exact wording found in the invocations. The reward may be tied to those specific letters, and a Muslim should supplicate with the reported wording. One can ask Allah for protection and well-being for their family in their supplications, and in the plural invocations, one can intend for Muslims generally.