What is the ruling of Islamic law on agreeing to pay a symbolic amount (a quarter Dinar) whenever one forgets to mention Allah during conversation, with the aim of reminding one of Him?

The remembrance of Allah is among the best deeds, and it has been commanded in the Qur'an and Sunnah, as Allah the Almighty says: "And the men who remember Allah often and the women who do so - for them Allah has prepared forgiveness and a great reward." The Prophet (peace be upon him) also encouraged remembrance, saying: "Let your tongue remain moist with the remembrance of Allah the Exalted." Therefore, a Muslim should frequently engage in remembrance through legitimate means and avoid innovated means that were not transmitted from the Salaf, due to the potential prohibitions that may result from them.