What is the authenticity and explanation of the hadith: "An 'awdhah (incantation/refuge) with which Ibrahim used to seek refuge for Isḥaq and Isma'il, and with which I seek refuge for Al-Hasan and Al-Husayn - may Allah be pleased with them both: 'May Allah hear the supplicant who supplicates; beyond Allah is no target for one who aims'"?

The hadith (definition) mentioned in the question: "A awdhah (supplication for protection) by which Ibrahim used to seek protection for Isaac and Ishmael (peace be upon them), and by which I seek protection for Hasan (definition) and Husayn (may Allah be pleased with them): 'Allah heard the one who called Him; there is no target beyond Allah for one who aims'" is weak in its chain of narration (isnaad), because it contains Nuaym ibn Murra al-Anbari, who is unanimously considered weak by the imams of hadith.

As for what is authentic in this regard, it is what Al-Bukhari narrated from Ibn Abbas that the Prophet (peace be upon him) used to seek protection for Hasan and Husayn, and say: "Indeed, your father [Ibrahim] used to seek protection for Ishmael and Isaac with it: 'I seek refuge in the perfect words of Allah from every devil and harmful creature, and from every evil eye.'" The meaning of "perfect words of Allah" is Allah's words in their entirety, without defect, or His decrees and promises. "Harmful creature" (haammah) refers to any soul that intends evil or any venomous creature that kills. "Evil eye" (ayn laammah) is every disease and affliction that befalls a person.