What is the ruling on saying to Allah in your supplication: "Be Merciful"?

The supplication "O Allah, do not make me wretched by Your supplication, and be to me Most Kind, Most Merciful" has been mentioned in some narrations, including one narrated by Al-Tabarani, which Al-Haythami deemed weak. Ibn Al-Qayyim also mentioned it in Zad Al-Ma'ad as part of the Prophet's supplication at Arafat. Its meaning is: "having the effects of Your attribute of kindness and mercy attached to me." There is no harm in using this wording in supplication, such as "O Allah, be merciful to me," for a supplication in the form of a command from the lower to the higher is considered a plea.