Is supplicating with "O Allah, in Your management there is what suffices against stratagems, and in Your generosity there is what is beyond hope. O Allah, O Protector of my blessing and my refuge in my distress, make what I fear and dread coolness and peace upon me, just as You made the fire coolness and peace upon Abraham" considered an innovation, and should one who says it be advised to abandon it?

The supplication mentioned has a good meaning but is not ثابتًا بالوحي (established through revelation). Therefore, it is permissible to supplicate with it occasionally, without considering it a fixed Sunnah or a regular litany, and without believing it to be superior to other Prophetic supplications. For acts of worship are built upon divine injunction and adherence, not on innovation. It must be noted that Prophetic supplications are the best and safest, and they suffice the Muslim. Adhering to others misses a lot of good and may involve polytheism. Among the Prophetic supplications in times of distress are: "لَا إِلَهَ إِلَّا اللهُ الْعَظِيمُ الْحَلِيمُ، لَا إِلَهَ إِلَّا اللهُ رَبُّ الْعَرْشِ الْعَظِيمِ، لَا إِلَهَ إِلَّا اللهُ رَبُّ السَّمَاوَاتِ وَرَبُّ الْأَرْضِ وَرَبُّ الْعَرْشِ الْكَرِيمِ" (There is no deity except Allah, the Great, the Forbearing. There is no deity except Allah, Lord of the Magnificent Throne. There is no deity except Allah, Lord of the heavens, Lord of the earth, and Lord of the Noble Throne), and "اللَّهُمَّ رَحْمَتَكَ أَرْجُو، فَلَا تَكِلْنِي إِلَى نَفْسِي طَرْفَةَ عَيْنٍ، وَأَصْلِحْ لِي شَأْنِي كُلَّهُ، لَا إِلَهَ إِلَّا أَنْتَ" (O Allah, I hope for Your mercy, so do not abandon me to my soul for the blink of an eye, and set all my affairs right for me. There is no deity except You), and the supplication of Dhul-Nun: "لَا إِلَهَ إِلَّا أَنْتَ سُبْحَانَكَ! إِنِّي كُنْتُ مِنَ الظَّالِمِينَ" (There is no deity except You. Exalted are You! Indeed, I was among the wrongdoers). A Muslim should strive to seek out Prophetic supplications, for they are the best example.