Is it a condition for performing a sunnah that its performer must be consistent with it?

Question:
If I want to apply a certain sunnah, I do not apply it unless I am certain that I will be consistent with it, such as the two rak'ahs of wudu', for example, acting on the saying of the Prophet (peace and blessings be upon him): "The best of deeds are those that are most consistent, even if they are few." What is your opinion, Honorable Shaykh, regarding what I am doing?

Answer:
Consistency is not obligatory. If consistency is achieved, there is good in it. If it is not achieved, a person does not leave off righteous deeds and voluntary acts; rather, he performs them even if he is not consistent with them. As for righteous deeds, if consistency with them is achieved and they are prescribed, this is a continuation of good and a greater abandonment. But if he is unable to be consistent or does not commit to it, he does not leave off acts of worship, saying, "I do not perform them," nor does he leave off voluntary acts, saying, "I do not perform them unless I am going to be consistent with them." Yes.