My wife was praying and i noticed that performed qawma and jalsa rapidly without being motionless i.e. she made the initqaal to the next stage when still in movement without being cutt of of movement.
Upon this i explained her that she must at least stand still for 2 seconds.
Then i said “if you going to pray the way you pray, then don’t pray at all.” (the intention behind this was to mean if you want to pray than pray it well, otherwise dont pray a salaat which is not accept conform the quran&hadith)
Do i have to make repetance of the last sentence i said, is it some kind of kufr (i get such whisperirs in my head) ?
Also how many seconds should one stay motionless between the intiqaals ? Please give of each madhab the amount of seconds.
Answer:
In the name of Allah, the most Beneficent, the most Merciful.
There is a difference in opinion in whether Tadeel Arkan is wajib or sunnah in the sitting between the two sajdahs (jalsah) and in the qawmah (the standing before going into ruku).
The strongest opinion and the most correct opinion is that it is wajib. (Raddul Muhtar p.157 v.2)
The Islamic ruling for staying “motionless” between each rukn or pillar of salah with the other is equivalent of one rukn. A rukn is the time t takes to read three subhanallahs.
Allah 
in the Holy Qur’an has said:
“Allah does not obligate anyone beyond his capacity.” (Surah Baqarah v.286)
There are two aspects to human deeds. One is an outward deed and the other is an inward deed. Each of these two aspects is further divided into two kinds. Voluntary and Involuntary. Examples of outwards deeds done voluntarily is to speak by choice or to beat somebody by choice where as saying something other than what one actually intended to say, or a palsied hand moving unintentionally caused pain to somebody.
Similarly, inward deeds which are voluntary is belief in kufr and shirk and non-voluntary, for instance the entry of some evil thought in one’s heart without an intention.
Voluntary deeds will be rewarded or punished. Similarly inwardly voluntary thought will be rewarded or punished. However, involuntary actions will not be subject to any punishment. (Maariful Quran p.722 v.1)
With regards to your question the statement you said to your wife would not constitute kufr. Your Imaan is intact and you should not worry about these evil whispers.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham