What is the correct wording for a vow (nadhr), and is saying, "If You fulfill this need for me, I will do such-and-such for Allah," considered a condition placed upon Allah and an impoliteness towards Him?

A vow (nadhr) is when a Muslim obligates themselves to an act of obedience that is not legally (shar'an) obligatory. It can be immediate (munjaz) or contingent (mu'allaq). A vow is contracted through phrases that indicate commitment, such as: "I have vowed to Allah" or "It is incumbent upon me for Allah." Initiating a vow is not recommended, and some scholars have explicitly stated its dislike (karahah). Nevertheless, if someone vows an act of obedience to Allah Almighty, they must fulfill their vow, especially if the vow is contingent upon the attainment of a blessing or the warding off of a misfortune.