What is the authenticity of the hadith: “That more than three movements in prayer invalidate it”?

Question:
My problem is that I move a lot during prayer. I have heard that there is a hadith meaning that more than three movements in prayer invalidate it. What is the authenticity of this hadith? And what is the way to get rid of excessive fidgeting in prayer?

Answer:
It is the Sunnah for the believer to devote himself to his prayer and be humble in it with his heart and body, whether it is an obligatory or voluntary prayer; because of the saying of Allah, the Exalted: who are humble in their prayers [Al-Mu’minun: 1-2]. And he must be at ease in it, and that is one of its most important pillars and obligations; because of the saying of the Prophet (peace and blessings be upon him) to the one who performed his prayer poorly and did not be at ease in it: He did this three times, so the man said: O Messenger of Allah, by Him who sent you with the truth, I do not know how to do anything other than this, so teach me. So the Prophet (peace and blessings be upon him) said to him: It is agreed upon that it is authentic.
And in a narration by Abu Dawud, it said in it: And this authentic hadith indicates that being at ease is a pillar in prayer and a great obligation in it, and it is not valid without it. So whoever rattles off his prayer has no prayer, and humility is the core and spirit of prayer, so it is prescribed for the believer to care for it and strive for it.
As for limiting the movements that contradict being at ease and humility to three movements, that is not a hadith from the Prophet (peace and blessings be upon him), but rather it is from the words of some of the scholars of knowledge, and there is no reliable evidence for it.
But fidgeting in prayer is disliked, such as moving the nose, the beard, and the clothes, and being occupied with them. And if the fidgeting becomes much and continuous, it invalidates the prayer. But if it is little by custom, or if it is much but not continuous, then the prayer is not invalidated by it, but it is prescribed for the believer to maintain humility and leave off fidgeting, whether little or much, striving for the completeness and perfection of the prayer.
And among the evidence that little work and few movements in prayer do not invalidate it, and likewise scattered work and movements that are not continuous, is what is established from the Prophet (peace and blessings be upon him): And it is established from him (peace and blessings be upon him) from the hadith of Abu Qatadah (may Allah be pleased with him) that he prayed one day with the people while carrying Umamah, the daughter of his daughter Zaynab, so he would put her down when he prostrated and carry her when he stood up. And Allah is the guarantor of success.