Punishment for Neglecting Prayer and Garment Below Ankle
8-4-2002 | IslamWeb
Question:
1) What is the punishment for the one who does not pray at all and the one who does not pray in its time? 2) What is the ruling regarding the part of the garment below the ankle?
Answer:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad 
is His slave and Messenger.
A person who denies that the prayer is an obligation is a disbeliever even if he performs it, since the obligation of the prayer is proven with absolute evidence and one of the incontestable fundamentals of Islam.
As for abandoning the prayer due to laziness or remissness, then the scholars of Islam differ and hold three different opinions:
1) Some scholars believe that whoever abandons the prayer, he/she should be jailed and disciplined until he/she performs the prayer.
2) Other scholars say that whoever abandons one prayer, he/she should be required to repent. So, if he/she repents, we leave him; otherwise, he/she should be killed; that being the prescribed punishment.
3) A third group say that the Imam of Muslims (i.e. the ruler) or his deputy should invite one who abandons his prayer to repent; if he/she refuses, he is to be killed since he/she becomes an apostate.
Here, we believe that the latter opinion is the dominant one due to the clear and strong evidence and the agreement of the Prophet's companions on such an opinion.
'Abdullah Ibn Shaqeeq reported that: “The companions of the Prophet did not consider the abandonment of any act, with the exception of the prayer, as being disbelief.” [at-Tirmithi]
Another Hadith reads: “The head of the matter is Islam, its pillar is the prayer, and the top of its hump is Jihad.” [at-Tirmithi who classified it as authentic]
Shaykh Ibn Taymiyyah 
said: “If the pillar of a tent has fallen, then the entire tent will fall down and it becomes useless.”
As for one who performs the prayer now and then, then he/she is not a disbeliever although he/she is in a very dangerous situation that necessitates punishment such as beating and imprisonment to deter him/her from such a bad action.
In addition, it is not permissible to delay a prayer from its prescribed fixed time without a genuine Islamic reason, such as sleeping and so on.
Allah has threatened those who delay the prayer in the Quran as He Says (what means): {So woe to those who pray. [But] who are heedless of their prayer -.} [Quran 107:4-5]
According to the opinion of many righteous predecessors, the word “woe” means torture and destruction to those who delay the prayer from its prescribed fixed times.
As for your second question, please refer to Fatwa 81448.
Also, for more benefit on the ruling on abandoning the prayer or delaying it, please refer to Fataawa 384457, 377344, 88016, 84178, 83565, 87587, 90926, 88690 and 84403.
Allah knows best.